The best gas bottle level indicators, compared.
Top pick: Avvchuy 6-pack magnetic strips Best value: Volnamal magnetic strip – Best value under £5: a printed 10-minute gas-on wait and 3.6 from 417 reviews, the largest strip sample in the set. Updated October 2026.
A gas bottle level indicator estimates how much liquefied petroleum gas remains in a portable propane or butane cylinder. In the UK you use one on an exchange bottle for a barbecue, a patio heater, a caravan or a motorhome. The low-cost tool is a magnetic liquid-crystal strip. It needs a steel wall and changes colour along the cold line while gas is flowing. Read it on the lower outside. An ultrasonic probe says whether liquid is present at one height, on steel or aluminium, inside a stated diameter. A magnet will not hold on aluminium or on a translucent composite bottle. Regulator pressure stays high until the bottle is nearly empty. Match the wall, the diameter and whether the appliance must be running. A colour step or a yes-or-no light is approximate. Weigh the cylinder and subtract the tare when the quantity has to be right. The order of those checks is in the [gas bottle level indicator buying guide](/hub/measuring-equipment/gas-bottle-level-indicator/sub/gas-bottle-level-indicator-buying-guide). A smell that remains is for a Gas Safe engineer qualified for LPG.
A gas bottle level indicator estimates how much liquefied petroleum gas remains in a portable propane or butane cylinder.
42 products checked · 58 hrs invested · +22,100 readers
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Personal buying guide
Question 1 of 2
What is the bottle wall?
The Avvchuy six-pack at £9.99 is six PET cards with a soft magnet, and the listing says the colour shows in about 10 minutes and returns to the original state in 1–2 minutes. Amazon shows 5.0 from three ratings, with two UK texts, both positive. One reviewer used the cards on camping bottles and barbecue cylinders instead of shaking the tank, and said the temperature-sensitive display matched a weight check. Neither written review describes a fault. Steel is not named, and the bullets do not say the appliance must be on. Three ratings cannot carry a 5.0 past a 417-review strip that sits at 3.6, which is why the score stays in the low thirties. The pack suits someone who wants a card on several tanks and will treat that one weight match as a household check, not as a percentage.
Pros
Cons
Best for: You have several steel tanks and you want a card on each, accepting only three reviews.
Less suitable: You are choosing on star rating alone, or the bottle wall will not hold a magnet.
Specifications
Common questions
How long does it take to show the level?
The listing says the level shows in about 10 minutes after you place the card. Colour returns to the original state within 1–2 minutes after a measurement.
Will the magnet damage the cylinder?
The listing notes ask this and do not answer it.
How accurate are the readings?
The bullets do not state an accuracy figure. One of two UK reviews says the temperature-sensitive display matched a weight check.
The Joyyhaus four-pack at £6.52 is four cards stated as 10 × 6.3 cm, and the bullets say to place the card and wait about 30 seconds. They do not say to turn the gas on. The temperature field is 0 °C to 40 °C, tighter than the −10 °C to 120 °C window on several other cards in this set. Amazon shows 5.0 from one rating, and there is no review text to show what that star refers to. A highlight line mentions propane and Calor, which does not become a steel limit. Four cards at this price are a pack count. A single star with no written review does not test the 30-second claim against a bottle that is actually cooling.
Pros
Cons
Best for: You want four spare cards and you will ignore the single star.
Less suitable: You want a 10-minute gas-on instruction that buyers have already argued with, or a bottle outside 0 °C to 40 °C.
Specifications
Common questions
Does it work with all gas bottle sizes?
The listing does not answer that. The strip size on the listing is 10 x 6.3 cm.
Is it suitable for propane and butane?
The bullets do not answer that. A highlight line mentions propane and Calor.
How long do you wait?
The bullets say place it on the bottle and wait about 30 seconds. They do not say to turn the gas on. The temperature field is 0 °C to 40 °C.
The Truma LevelCheck is a handheld ultrasonic probe at £74.99 that lights an LED when liquid gas is in the measuring range, on steel and aluminium cylinders from 200 mm to 350 mm. Across 686 amazon.co.uk ratings it sits at 4.3, and the first 50 UK reviews mostly describe a green or red answer in seconds in a caravan or motorhome locker. Reviewers who checked it against a new bottle, a part-used bottle, or a weight reading treat that yes-or-no as enough to travel with one cylinder. The same notes repeat the limits: hold the tip straight on a clean wall, one LED is hard if you are colour-blind, and some users only trust it on a 6 kg or 11 kg bottle. One review reports gas indicated where there was none, and another found a 13 kg patio bottle awkward. The listing power field says gas powered, while a reviewer names a 9 V smoke-alarm battery rather than a PP9, so you should see which cell is in the box. At 200 g on the listing it is a tool you carry between bottles, and the bullets say it is not for refillable tank bottles.
Pros
Cons
Best for: You want a yes-or-no liquid check on steel or aluminium cylinders inside 200–350 mm, without leaving a card on each bottle.
Less suitable: You need kilograms, the cylinder is wider than 350 mm, or the bottle is plastic, a refillable tank, or Campingaz-type butane.
Specifications
Common questions
Can it measure gas in aluminium bottles?
The listing says steel and aluminium cylinders from 200 to 350 mm diameter. It is not for refillable tank bottles.
Does it need batteries?
A reviewer says the cell is a 9 V smoke-alarm battery, not a PP9. The listing power-source field says gas powered, which conflicts with that review.
Do you have to run the appliance?
The listing bullets do not require gas to be flowing. You place the meter horizontally on the bottle.
The Volnamal card is a single magnetic strip at £3.99, and the instructions say to clean the lower half, turn the gas on, and wait 10 minutes before you read the bars. The amazon.co.uk line is 3.6 from 417 ratings, the largest strip sample in this set, with the left bar for winter and the right bar for summer. In the first 50 UK reviews, some people report an early warning on a caravan bottle or a portable heater once the regulator is on. Others see every bar coloured, or a full reading on an empty 13 kg bottle. One reviewer found the card too big for their bottles, and another found it useless on a 47 kg propane tank. The listing does not name steel, the material field says propane, and the product-dimensions field prints 22 × 20 × 20 cm against a 10 g card. Use it as a cheap check while gas is flowing, and weigh the cylinder when both the colour step and the trip matter.
Pros
Cons
Best for: You want a cheap strip for a steel barbecue or caravan bottle and you will run the gas for 10 minutes before you trust a colour step.
Less suitable: You need a kilogram figure, the wall is aluminium or composite, or you will read the card with the appliance off.
Specifications
Common questions
Can it be used on butane cylinders?
The bullets say it is reusable on LPG propane and butane, with a magnetic backing for exchange bottles.
Does it need batteries?
The bullets do not list a battery. A question line asks whether it needs batteries and does not answer it.
How long before you can read it?
The instructions say turn the gas on and wait 10 minutes. In winter the left bar is active; in summer the right bar is active.
The OOBRAN card is the lowest shelf price in the set at £3.95, with the same style of instruction as the Volnamal: lower half, gas on, wait 10 minutes, left bar in winter and right bar in summer. Amazon shows 3.5 from 34 ratings, and the captured reviews are seven UK texts. A few of those say the reading looked true, including one person who moved the card onto the next exchange bottle. Others followed the instructions on two bottles and got no indication at all. Steel is not named. The power-source field says gas powered, and the card is listed at 15 × 10 × 0.2 cm, larger than the 10 × 6.3 cm strips in the multi-packs. At this price the risk the 34 ratings already show is a blank card, on the same temperature method as the dearer strips. It is a spare magnet for a barbecue cylinder you already know is steel.
Pros
Cons
Best for: You want the cheapest card in this set that still prints a 10-minute gas-on method, for a steel bottle you already use.
Less suitable: You want the larger set of reviews, or the wall does not attract a magnet.
Specifications
Common questions
Can it be used on a caravan?
The title names a caravan and a motorhome. The instructions are written for a cylinder while you use the barbecue.
Does it work with butane?
The bullets say LPG propane and butane.
Is it reusable?
The bullets say it is reusable, with a magnetic backing for exchange bottles. Place it on the lower half, turn the gas on, and wait 10 minutes.
The Dongnesi listing is two PET cards with a soft magnet at £5.89, each about 10 × 6.3 cm, and the bullets say to stick them on the outside with no installation. Steel, a wait, and a line about the gas being on are absent. Amazon shows 3.2 from 54 ratings, and 14 UK texts in the listing notes mostly say there was no colour change on full and empty bottles. One reviewer found the cards too small to read, another had no instructions, and one said the magnet did not stick and there was no level on propane bottles. A few short reviews call the pack handy, and one says to take the strips off when you change the bottle. The temperature field prints −10 °C to 120 °C, which is a crystal window, not a level tolerance. For £5.89 you get a second card, and the review notes say many of those cards do not show a step.
Pros
Cons
Best for: You already know the 10-minute method from another card and you only wanted a spare pair to try.
Less suitable: You need the listing to say steel and gas-on, or you want a review pattern that mostly tracks a level.
Specifications
Common questions
Can it be used on any gas bottle?
The listing does not answer that. The title names butane, propane, and LPG. Steel is not stated.
Does it work with propane?
The title says propane. One review says the magnet did not stick and there was no level result on propane bottles.
Is it easy to install?
The bullets say stick it on the outside of the cylinder, with no installation.
The Cowiny three-pack at £6.49 is the strip in this set that tells you to check the magnet on a suitable steel cylinder and to read it on the lower outside while gas is flowing. The bullets call the result an approximate reference that varies with surface, temperature, weather, and flow. The amazon.co.uk line is 2.0 from two reviews, and both texts are negative. One reviewer found the colour change so faint that shaking the bottle was easier, and said the full-to-empty wording does not follow the columns. The other ran three barbecue burners for ten minutes at 15 °C, saw no shift, and checked with an infrared thermometer that the wall had not cooled, while a fridge and the sun did move the columns. That sample is too small to rank the card, and it is large enough to show the crystals can react when the bottle does not. The steel sentence on the listing is the reason to read this page, and the two reviews are the reason to weigh the cylinder anyway.
Pros
Cons
Best for: You want the listing that states a steel magnet check, and you will still weigh the bottle.
Less suitable: You want enough written reviews to judge a colour step, or the cylinder is not steel.
Specifications
Common questions
Does this work with all gas cylinder types?
The bullets limit it to a suitable steel cylinder for propane, butane, and LPG. Check that the surface attracts the magnet.
How accurate is it?
The bullets call it an approximate reference, not a precise instrument. Results vary with material, surface, temperature, weather, and flow.
When can you read it?
Read it while gas is being used, on clean, dry steel, on the lower outside of the cylinder.
The Rivvra listing at £5.99 describes a magnetic liquid-crystal strip for the lower outside of compatible steel bottles, readable while gas is flowing, and transferable between steel cylinders. There is no amazon.co.uk rating line and no review text, so the steel wording has not been checked by buyers in these notes. The included-components field says 1, while the title says strips and gives no count. The model field reads “KR--Finger Pulse Oximeter”, which does not match a gas card. The item-dimensions field is 1 × 11 × 1 cm at 80 g. Until there are reviews, the steel and flowing-gas lines are the useful part of the page, and the model number is a reason to read the listing twice before you pay £5.99.
Pros
Cons
Best for: You have confirmed the delivered item is a steel-bottle strip and you only needed that wording.
Less suitable: You want a reviewed card, or you are buying from the title without checking the model field.
Specifications
Common questions
Does it work on all cylinder sizes?
The listing does not answer that. The bullets say compatible steel bottles, attached to the lower outside.
When does it work?
The bullets say it works while gas is flowing, and that the cylinder can stay connected.
How many strips are in the pack?
The included-components field says 1. The title says strips and does not give a count.
The GzGengHe three-pack at £6.59 is three PET cards, 10 × 6.3 × 0.1 cm, with a soft magnet and no battery. The listing says an instant reading after you attach the card, and it names most standard propane and butane cylinders for household use and for a caravan or motorhome. There is no rating line and no review text. Steel is not stated. An instant claim skips the evaporation wait that the reviewed cards print as 10 minutes, so the timing on the page does not match the strips that already have buyer comments. The temperature field is −10 °C to 120 °C. At £6.59 you are buying three unreviewed cards, and the only check available before delivery is the wording on the listing.
Pros
Cons
Best for: You want three unreviewed cards and you will still run gas long enough for a wall to cool.
Less suitable: You are buying the word instant as a faster method than a 10-minute strip.
Specifications
Common questions
How soon does it show a level?
The listing says an instant reading after you attach the card. It does not give a minute count.
Does it need tools or a battery?
The bullets say no tools, with a soft magnetic backing. The battery field is no.
Which cylinders does the listing name?
Most standard propane and butane LPG cylinders, for household use and for a caravan or motorhome. Steel is not stated as a limit.
The Ruiunchu listing at £7.99 is five magnetic cards for propane tanks, with a colour change and a magnetic back. There is no rating line and no review text. The listing also carries percent and digital fields that the bullets do not explain, and a count field says 1 while the title says five. Wall material, a wait, and a battery are not stated. The operation-mode field says manual. Heat and corrosion resistance are claimed without a temperature window in the technical details. Five cards do not become a percentage gauge because a field on the page says percent. Until the bullets describe a colour step, a steel wall, and a wait with gas flowing, this is a pack-count listing with extra words.
Pros
Cons
Best for: You have already seen the delivered cards and you only needed spares for propane tanks.
Less suitable: You are treating a percent field on a battery-free card as a measured level.
Specifications
Common questions
How accurate are these indicators?
The listing does not answer that. It also carries percent and digital fields that the bullets do not explain.
Does it work on all bottle sizes?
The listing does not answer that. The bullets say it is designed for propane tanks.
Does it need a battery?
A battery is not stated. The operation-mode field says manual.
The YG-YUNCHUANG three-pack at £5.59 is three black PET strips, each stated as 10 × 6.3 cm, with a liquid-crystal layer and no battery. The bullets say to clean the cylinder, attach the strip, and monitor it during use, for camping, a motorhome, or a caravan. There is no rating line and no review text. A listing accuracy field says the level is within about 10 percent of remaining capacity, and nothing in the listing notes checks that figure. Steel is not stated. The product-dimensions field prints 4 × 2 × 1 cm against a 10 × 6.3 cm strip, so the page disagrees with itself on size. Treat the 10 percent line as catalogue text. If you need a quantity, weigh the bottle and subtract the tare.
Pros
Cons
Best for: You want three plain cards and you will ignore the 10 percent line.
Less suitable: You are buying a stated percentage of gas left.
Specifications
Common questions
What is in the pack?
Three reusable black magnetic strips. Each strip is stated as 10 x 6.3 cm.
How do you use it?
Clean the cylinder surface, attach the strip magnetically, and monitor the indicator during use.
How accurate is the listing claim?
A listing field says within approximately 10 percent of remaining capacity. There are no reviews in the listing notes. Steel is not stated.
The Linswell three-pack at £5.59 is sold in the title as LinCoo, while the manufacturer field is Linswell. Each strip is stated as 10 × 6.3 cm, PET with a liquid-crystal layer, and no battery. The listing names a caravan, motorhome, camping, and a barbecue, and it does not name steel or a wait. There is no rating line and no review text. The accuracy field says ±2 °C, which is a temperature figure, not a statement of how much gas is left. The package-dimensions field is 4 × 2 × 1 cm, which does not match a 10 × 6.3 cm strip. Two brand names and a temperature tolerance are what the page adds to an unreviewed three-pack at the same £5.59 as the YG-YUNCHUANG set.
Pros
Cons
Best for: You have matched the title brand to the parcel and you only wanted spare cards.
Less suitable: You are reading ±2 °C as accuracy of the gas reading.
Specifications
Common questions
What is in the pack?
Three black magnetic strips. The title brand is LinCoo. The manufacturer field is Linswell.
Where does the listing say it fits?
Caravan, motorhome, camping, and barbecue. Steel and a wait time are not stated.
What does the accuracy field say?
The listing accuracy field says ±2 °C. There are no reviews in the listing notes.
Twelve gas bottle level indicator listings on amazon.co.uk were scored from the listing facts and UK review notes captured around 20 October 2026. No lab test was run. Review volume, method match, stated limits and review sentiment are weighted 40, 25, 15 and 20. Deductions, up to 12 points, cover a model number that names another product, a pack count that contradicts the title, and a percent or temperature field offered as a level. A 5.0 from one, two or three ratings cannot outrank a 4.3 from 686 or a 3.6 from 417. Shelf prices are the figures on those listings.
Review volume
40%Up to 40 points from how many amazon.co.uk ratings sit behind the star line. A line with 100 or more ratings can use most of this block. Fewer than ten ratings are capped, even at 5.0. No rating line scores 0.
Method match
25%Up to 25 points for whether the stated method matches the bottle. An ultrasonic check on steel and aluminium, with a diameter window, scores the full block. A strip that names steel and a reading while gas is flowing scores 18. A strip that prints a wait with the gas on, and does not name steel, scores 14. A colour-only card with no wall and no flow scores lower.
Stated limits
15%Up to 15 points for limits the listing actually prints. A diameter window, or a line that calls the result approximate, scores high. A winter and summer bar note scores 10. A 10 percent or ±2 °C field on a battery-free card does not add points.
Review sentiment
20%Up to 20 points from what the written UK reviews say. A large file that mostly works, with named faults, scores above a split file. A run of no-colour reviews scores lower. Two negative texts score low. No reviews score 0.
Start with the bottle wall, then what the reading actually is, then whether the appliance must be on, then the diameter and the pack. The notes below follow that order for these twelve listings. None of the scores is a laboratory test.
A gas bottle level indicator estimates how much LPG is left in a portable propane or butane cylinder. UK buyers are caravan and motorhome owners, barbecue and patio-heater users, and households on exchange bottles. The cheap tool is a magnetic liquid-crystal strip that sticks to steel and changes colour at the cold line while gas is flowing. Quality is not a higher star on the same strip.
The colour boundary needs evaporation. Thermographic notes on this method say it works only while gas is used. A warm card with every bar coloured is not a full bottle.
Steel holds the card. Aluminium, plastic, and a translucent composite bottle do not. Place the card on the lower outside, not on the shoulder, if you want a low warning.
Vapour pressure stays high until the liquid is nearly gone. A regulator gauge is not a half-full reading. Weigh the cylinder and subtract the tare on the collar when you need a figure.
A magnet needs steel. If the wall does not attract the magnet, a colour card cannot show a cold line. Aluminium needs a probe or scales. Composite bottles are translucent and do not take a magnet, and on those you often see the liquid instead of measuring it. The ultrasonic listing in this set states steel and aluminium cylinders from 200 mm to 350 mm, and it says it is not for refillable tank bottles. A 47 kg cylinder is wider than that window on published UK dimension tables.
Strips need evaporation, so the appliance must be on. Instructions that are specific say clean the lower half, turn the gas on, and wait about 10 minutes. Winter and summer bars are named on two single cards. A 30-second wait that never says to turn the gas on is a different claim, and a single star with no written review does not test it. An instant claim skips the wait the reviewed cards print. Probes in the bullets do not require a long burn.
Three typical situations, each with a recommendation from this comparison.
You want a yes-or-no liquid check on steel or aluminium cylinders from 200 mm to 350 mm, without leaving a card on each bottle. The Truma LevelCheck is about £74.99, with 4.3 from 686 amazon.co.uk reviews. The bullets do not require the gas to be flowing. It is not for plastic, a refillable tank, or Campingaz-type butane.
You want a cheap magnetic strip and you will run the gas for 10 minutes before you read the bars. The Volnamal card is about £3.99, with 3.6 from 417 reviews, the largest strip sample here. The listing does not name steel. Weigh the cylinder when the colour step and the cook both matter.
You want the strip that tells you to check the magnet on a suitable steel cylinder and calls the result approximate. The Cowiny three-pack is about £6.49. The star line is 2.0 from two reviews, and both texts failed to get a clear step. The steel sentence is why it is here. The two reviews are why you still weigh the bottle.
The top pick is the Truma LevelCheck at about £74.99. It is the only ultrasonic meter in the set, stated for steel and aluminium from 200 mm to 350 mm, and amazon.co.uk shows 4.3 from 686 reviews. The listing power field says gas powered, while a review names a 9 V cell. Best value is the Volnamal magnetic strip at about £3.99. The instructions say turn the gas on and wait 10 minutes, and the star line is 3.6 from 417 reviews, the largest strip sample here. Reviews still split on whether the bars track an empty bottle, and the listing does not name steel. None of these scores is a lab test.
Volnamal magnetic strip
Best value under £5: a printed 10-minute gas-on wait and 3.6 from 417 reviews, the largest strip sample in the set.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources from the research digest, last checked around 20 October 2026. Shelf prices and star lines are the amazon.co.uk figures captured with these twelve listings. The price bands are this set, not a market average.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the UK listings checked around 20 October 2026. We did not lab-test these gas bottle level indicators.
