The best folding rulers, compared.
Top pick: Belle Fang folding ruler, 30 cm, pack of 2 Best value: Helix Oxford folding rule, pack of 2 – £5.49 for two named rules, 4.6 from 237 reviews. The open length is not stated. Updated 22 October 2026.
A folding ruler is a rigid measure made of hinged strips. In the UK that name covers a 1 m or 2 m carpenter’s rule and a 30 cm folder for a pencil case. None of the twelve prints an accuracy class. Tell the rows apart by open length, by whether the hinge is described as opening flat, and by the scale. Those reviews also describe a hinge that snaps and a gap that can kink a line past 15 cm. The [folding ruler buying guide](/hub/measuring-and-marking-tools/folding-ruler/sub/folding-ruler-buying-guide) puts length first, then the hinge, then the scale. A site folding rule is usually 1 m or 2 m, with joints that lock, for joinery and layout. A school folding ruler is two leaves, about 30 cm open and about 15 cm shut, in acrylic, soft plastic, or a thin metal strip, sometimes with a snap hinge or a claimed 180° joint. A 1 m or 2 m rule is outside these twelve, so the table does not crown a UK site rule.
A folding ruler is a rigid measure made of hinged strips. In the UK that name covers a 1 m or 2 m carpenter’s rule and a 30 cm folder for a pencil case. None of the twelve prints an accuracy class.
42 products checked · 58 hrs invested · +21,400 readers
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Personal buying guide
Question 1 of 2
What length do you need?
Belle Fang P002 is £5.49, with bullets describing two shatterproof plastic rulers, 30 cm open and 15 cm folded, at 20 g. The number-of-items field says 1, so the pack count and the items field disagree and you should confirm two rulers are in the box. amazon.co.uk shows 5.0 from 2 reviews. Both written reviews are short and positive: they say the scale is centimetres, the rulers are light and flexible, and one buyer calls them sturdy and not easy to snap at the £5.49 price. Neither review describes a gap or a bent hinge. Two positive texts cannot show how the hinge lasts a term, and the listing does not claim imperial marks. Flexible plastic is a different job from a locked metal edge.
Pros
Cons
Best for: You want two flexible 30 cm centimetre rulers that fold to 15 cm, and you can accept two reviews.
Less suitable: You need imperial marks, a locked metal rule, or a long review history.
Specifications
Common questions
How long is it folded?
The bullets and both reviews say 15 cm folded and 30 cm open. One review says they measure in centimetres only.
How many are in the pack?
The title and the pack count say 2, and a review received two. The number-of-items field says 1.
What do the two reviews say?
Both are positive. They call the rulers clear, light, and useful. Neither describes a snap or a bad scale.
The Liravonte four-pack is £5.39 and lists 17 g across pastel green, blue, pink, and grey. Bullets say shatterproof plastic, 30 cm open and 15 cm folded, a centimetre scale, and shapes such as squares and circles, with no degree range. amazon.co.uk shows 5.0 from 1 review. There is no written review text with the listing, so the star line is a single vote and says nothing about hinge life. Technical questions on the listing about readable scales and even folding are unanswered. Four rulers at this price look cheap per piece only if the plastic and the fold match the bullets when they arrive. There is no metal edge and no site length on the listing.
Pros
Cons
Best for: You want four coloured 30 cm folders that the listing says fold to 15 cm.
Less suitable: You want review evidence, or a metal or site rule.
Specifications
Common questions
How small does it fold?
The bullets say 30 cm open and 15 cm folded. Weight is 17 g for the listing.
Is it shatterproof?
The bullets say shatterproof plastic that helps prevent finger scratches. There is no written review text to check that claim.
Are there written reviews?
The listing line is 5.0 from 1 review. There is no written review text with the listing.
The Helix Oxford J05011 pack is £5.49 for two silver rules whose material field says Metal and whose listed weight is 70 g. Open length and scale are not in the spec fields, and the printed questions on metric marks and carpentry are unanswered. This row does not state a 30 cm length. amazon.co.uk shows 4.6 from 237 reviews. Sixteen Amazon reviews call the markings clear, mention school and a shirt pocket, and treat a spare in the pack as useful. Those same reviews call the hinge the weak point: one household describes countless snaps, and others say a rule broke within the first few uses. No scale-gap complaint appears in those 16 texts. It is the best value in this table when you want a named Helix spare at about £2.75 each and you will check the open length in hand.
Pros
Cons
Best for: You want two metal Helix folding rules at £5.49 and you can check the open length in hand, because the listing does not state it.
Less suitable: You need a printed 30 cm or 2 m length, or a scale the listing actually names.
Specifications
Common questions
What is this Helix pack made of?
The material field says Metal. The colour field says Silver. The listing does not name aluminium or steel separately.
How long is it when open?
The title is Helix J05011 Oxford Folding Rule, pack of 2. It does not print 30 cm, and the graduation field is missing. Folded length is not stated.
What do the reviews repeat?
Sixteen of 237 reviews are written out with the listing. They praise clear marks and school use. They also say the hinge snaps, including more than once in the same household.
OX-P507201-E is the only 600 mm rule in this set, sold as a cyan twin pack at £14.99. The bullets describe solid ABS, a reinforced brass hinge, four leaves of 150 mm, an integrated centre line, and a swivel from 0° to 180°. Listed weight is 180 g, the dimensions field says 60 x 4.5 cm, and the origin is China. amazon.co.uk shows 4.6 from 45 reviews. Nine Amazon reviews call it useful where a tape is awkward, stiff rather than floppy, and easy to see in a toolbox, with one buyer mentioning the centre-line notches. One UK review found mould on arrival and said the hinge was stiff to open. Questions on the listing about angles past 180° and left-handed use are unanswered. It is the framing option here. Nine texts are a small sample for the mould note.
Pros
Cons
Best for: You want a 600 mm metric folding rule with an angle hinge for framing, and a second one in the same pack.
Less suitable: You need a 2 m rule, or a 30 cm ruler for a pencil case.
Specifications
Common questions
How long is the OX rule?
The title and the graduation field say 600 mm. The bullets say four folds of 150 mm. That is 600 mm.
Does it measure angles past 180°?
The bullets say a 0–180° swivel hinge. Questions on the listing about angles past 180° and left-handed use are unanswered.
What do the reviews say?
Nine of 45 reviews are written out with the listing. They call it handy where a tape is awkward, and they like the stiff hinge and the cyan colour. One UK review mentions mould on arrival.
HRLORK F-E-ZDCZ01 is £3.99 for two clear 30 cm rulers at 30 g, with a 180° joint claimed in the bullets. amazon.co.uk shows 4.6 from 20 reviews, and only two of them are written out with the listing. One calls the pair fiddly and not as sturdy as hoped, and says they sit slightly off 180°, by a degree or two. The other prefers them to a flexi ruler that warps in a pencil case, even though the review title talks about fragility. Neither of those two texts describes a snap. Twenty stars with only two written texts is a thin basis for a school year, so check the open edge against a known straight line before you mark anything you will cut.
Pros
Cons
Best for: You want two clear 30 cm folders at £3.99 and you can live with a thin review sample.
Less suitable: You need a straightedge you have checked, or a site rule.
Specifications
Common questions
Is there a protractor?
The bullets say a built-in 180° protractor at the joint. One of the two written reviews says the rulers sit a degree or two off 180°.
How many are in the pack?
The title, the pack count, and the number of items all say 2. Weight is 30 g for the listing.
What do the reviews say?
Only two of 20 reviews are written out with the listing. One calls them fiddly. The other prefers them to flexi rulers and notes they are slightly off straight.
The cersalt rule is £8.87, with a stainless-steel material field, a weight of 30 g, and a graduation of 300 mm. Bullets say the error is about ±0.02 mm, mention laser calibration, and name glass processing and school, without an accuracy class. The dimensions field says 30 x 30 cm, which is a square and does not match a 300 mm folding rule, so leave that row out of the folded size. A bullet talks about chamfer angles if you ask, and it does not state a fixed protractor. amazon.co.uk shows 4.6 from 2 reviews. There is no written review text with the listing, so none of the industry or school claims is confirmed by a UK buyer in this set. At £8.87 it costs more than the Helix acrylic ruler that has thousands of reviews, and the buy rests on the title length.
Pros
Cons
Best for: You want a stainless 300 mm stationery rule and you will check the size, because the dimensions field is 30 x 30 cm.
Less suitable: You want reviews, a folded length, or a class mark.
Specifications
Common questions
What is it made of?
The material field and the bullets say stainless steel, described as rust-resistant. Weight is 30 g.
Can it measure angles?
One bullet says chamfer angles are available if you tell the seller. It does not state a 90° or 180° scale.
Are there written reviews?
The listing line is 4.6 from 2 reviews. There is no written review text with the listing. The dimensions field says 30 x 30 cm, which does not match a 300 mm title.
This Generic set, model NCJ-784, is £7.99 for three rulers listed at 20 g with dimensions 16 x 7 cm. Bullets say 30 cm open, 15 cm folded, and soft K-glue plastic. The colour field and the bullets name different colours, so you cannot order a specific shade from the page as it stands. amazon.co.uk shows 4.5 from 2 reviews. There is no written review text with the listing, which leaves the hinge, the softness, and the colour clash unchecked. At £7.99 it costs more than several two-packs in this table that at least have written reviews. It suits you only if you want three soft folders and you will look at the colours when the parcel arrives.
Pros
Cons
Best for: You want three soft 30 cm folders and you can check the colours on arrival.
Less suitable: You want a named brand, a metal edge, or written reviews.
Specifications
Common questions
What colours are in the set?
The colour field says White/Pink/Blue. The bullets say blue, red, and transparent. The listing does not resolve that.
Is it shatterproof?
The bullets say soft K-glue plastic, shatterproof, with no sharp edges. There is no written review text.
Are there written reviews?
The listing line is 4.5 from 2 reviews. There is no written review text with the listing.
Helix J05100 is the 30 cm acrylic folding ruler in this set, listed at £4.44 with a snap-fit hinge and a weight of 40.8 g. The bullets put metric and imperial marks on a two-colour print, and the graduation field says 30 centimetres. amazon.co.uk shows 4.4 from 3,635 reviews, and the listing ranks it 6 in Rulers under Stationery. In the first 50 of those reviews, buyers like the pencil-case size, the click when it shuts, and the clear numbers, including for GCSE maths. The same sample says the hinge snaps after days, weeks, or a term, especially if it is sat on or folded the wrong way. A gap at the joint, or one end sitting slightly lower, makes a line longer than 15 cm swerve, even though some buyers say theirs stays straight. One review was sent a flexible ruler instead, so the photo is not a guarantee of what arrives. It is the top pick here because of that review depth at £4.44. The hinge is described as snapping in that sample.
Pros
Cons
Best for: You want a 30 cm acrylic folding ruler for a pencil case, with metric and imperial marks, at £4.44.
Less suitable: You need a 1 m or 2 m site rule, or a hinge that the reviews do not describe as snapping.
Specifications
Common questions
Does this Helix ruler show metric and imperial?
Yes. The bullets say both metric and imperial graduations, with a two-colour print. The graduation field says 30 centimetres.
What is the hinge?
The bullets say a folding snap-fit hinge. Reviews mention a click when it shuts. The same reviews also include snaps at that hinge.
What do the reviews repeat?
The first 50 of 3,635 reviews praise the pencil-case size and the clear marks. They also report the hinge snapping, and a gap so a line longer than 15 cm swerves.
BTOPB UK-D014 is the lowest shelf price in the set at £2.78 for one clear plastic 30 cm ruler listed at 10 g. The title also says 12 inch, the bullets claim a shatter-resistant plastic and a joint that measures angles up to 180°, and the package dimensions are 16.9 x 3.1 x 0.7 cm. Folded length is not a stated measurement, only a pencil-case claim. amazon.co.uk shows 4.0 from 5 reviews. There is no written review text with the listing, so there is no UK comment on snaps, gaps, or whether the 180° joint holds a line. A software-updates field says unknown, which does not belong on a ruler and shows how thin the listing is. Buy it only if £2.78 matters more than any written evidence of how the hinge behaves.
Pros
Cons
Best for: You want the cheapest 30 cm folder in this set and you accept that the listing notes have no review text.
Less suitable: You want review evidence, or a site rule.
Specifications
Common questions
Does the joint measure angles?
The bullets say the folding joint measures angles up to 180°. There is no written review with the listing to confirm that.
What is it made of?
The material field says Plastic. The bullets say shatter-resistant plastic. Weight is 10 g.
Are there written reviews?
The listing line is 4.0 from 5 reviews. There is no written review text with the listing, so praise and faults are not stated.
The Guagua two-pack is £3.79 for clear 30 cm folders listed at 30 g, with dimensions 16 x 3.5 cm and a 180° joint in the bullets. A bullet also prints 30 cm/30 mm, which cannot both be the open length, so treat 30 cm as the title figure. amazon.co.uk shows 3.9 from 203 reviews. Forty-six Amazon reviews praise the pencil-case size and, for some buyers, the angle labels on the joint. The same sample is blunt about failure: both rulers in a pack snapped within two weeks, a month, or on the first day of school, and several will not unfold straight, so a length past 15 cm sits on a bump. Markings are called small, with moulded dots where the numbers are, and one of a pair arrived chipped. At this price you are buying a spare. A straightedge for a graph or a cut needs a hinge you have checked.
Pros
Cons
Best for: You want two cheap clear folders for a pencil case and you have read the snap reviews.
Less suitable: You need a ruler that stays straight past the hinge for graphs or a cut.
Specifications
Common questions
Is it 30 cm or 30 mm?
The title says 30 cm and 300 mm. One bullet says 30 cm/30 mm. Those two figures do not match. Treat 30 cm as the title figure.
Does the joint show angles?
The bullets say the junction is a protractor to 180°. Reviews mention angle labels. Several also say it does not open straight.
What do the reviews repeat?
Forty-six of 203 reviews are written out with the listing. Praise is the pencil-case size and the angle labels. The repeated fault is a snap within days, or a ruler that will not lie flat.
The Akozon black ruler is £8.44, 30 g, and 16 x 2.5 cm, with bullets that claim 0–150 mm folded, 0–300 mm open, 0–90°, and an error of about ±0.02 mm. The material field says Aluminium while the bullets also say stainless steel, and no accuracy class is printed, so the ±0.02 mm line is a seller sentence. amazon.co.uk shows 3.8 from 172 reviews. Thirty-eight Amazon reviews include buyers who like the pencil-case size and a white-on-black scale, and a few who checked the marks against another 30 cm rule. The repeated complaint is a gap between 15 cm and 16 cm, or about 1 cm extra past the swivel, and a hinge that will not stay straight for a line longer than 15 cm. Nothing in the bullets describes a lock, and reviews say it moves while you draw. One buyer measured a closed size of about 25 mm by 160 mm, which is close to the 16 x 2.5 cm field and still your own check.
Pros
Cons
Best for: You want a small black metal folder for a pencil case and you will check the hinge against another rule before you trust it.
Less suitable: You need a continuous scale past 15 cm, or a figure tighter than a seller’s ±0.02 mm line.
Specifications
Common questions
Is the 30 cm scale continuous?
The bullets say 0–150 mm folded and 0–300 mm open. In 38 of 172 reviews, several describe a gap between 15 cm and 16 cm, or about 1 cm extra past the hinge.
What metal is it?
The material field says Aluminium. The bullets also say stainless steel. Both stay on the listing.
Does it lock open?
The bullets do not describe a lock. Reviews say nothing holds it at 180°, and that the joint bends with use.
SouStar’s khaki ruler is £6.99 and 24 g, with bullets that claim 0–150 mm folded, 0–300 mm open, and an L-shape from 0° to 90°. The same bullets name both stainless steel and a non-rust aluminium alloy, and they do not print an accuracy class. amazon.co.uk shows 1.0 from 1 review. That single review says the ruler broke the first time it was used, and it does not comment on the scale or the 90° stop. That review is the only written evidence with the listing. Questions about a locking hinge are unanswered. At £6.99 with a one-star review, read that review before you buy this khaki page.
Pros
Cons
Best for: You specifically want this khaki 30 cm metal listing and you have read the one-star review.
Less suitable: You want a ruler with more than one review, or a stated accuracy class.
Specifications
Common questions
Does the hinge lock?
Whether the hinge locks firmly is an unanswered question. The bullets claim a 0–90° L-type ruler. They do not describe a lock.
What metal is it?
The bullets say stainless steel and also a non-rust aluminium alloy. The listing does not pick one.
What does the review say?
The only review says it broke the first time it was used. The listing line is 1.0 from 1 review.
For this comparison we read twelve amazon.co.uk folding-ruler listings and the UK review notes that sit with them. The scores come from the star line and the review count, then a reading of listing fit, review outcome, and price against a job the listing supports. This is not a laboratory test, and none of the twelve prints Class I, II, or III.
Amazon evidence
40%The star line and the review count on amazon.co.uk. A 5.0 from one or two reviews does not outrank a large sample such as 4.4 from 3,635.
Listing fit
25%A stated 30 cm or 600 mm length, a named scale, and a described hinge score up. An unstated open length, a 30 cm/30 mm clash, a 30 x 30 cm dimensions row, or steel and aluminium in the same bullets come off. A seller line of about ±0.02 mm is not a class.
Review outcome
20%UK review text only. A pencil-case fit and clear marks score up. A repeated hinge snap, a gap past 15 cm, or a rule that will not lie straight comes off. No written review text means the stars carry less weight.
Value
15%Shelf price in GBP against a job the listing and the UK reviews support. £4.44 with thousands of reviews is the evidence line. £5.49 for two named rules is the value line. £14.99 is the only 600 mm framing pack.
Use open length first. A pencil-case folder, a 600 mm layout rule, and a 1 m or 2 m site rule are different buys that share a name. This table is the twelve amazon.co.uk rows: mostly 30 cm folders from £2.78 to £8.87, and the OX twin pack at £14.99. Match the hinge and the scale to the mark you will actually make. A quality site rule is the one that states an accuracy class. None of these twelve does. Prices outside this set move, so treat a best-seller snapshot of 1 m and 2 m rules as context.
A folding ruler is a rigid measure made of hinged strips. It packs short and opens straight. In the UK that name covers two different buys. A site folding rule is usually 1 m or 2 m, with joints that lock, for joinery and layout. A school folding ruler is two leaves, about 30 cm open and about 15 cm shut, in acrylic, soft plastic, or a thin metal strip, sometimes with a snap hinge or a claimed 180° joint.
A 30 cm folder is a pencil-case length. Stud layout and a usual site rule sit at 1 m or 2 m, which is outside this set. The only framing length here is the OX pack at 600 mm.
Reviews on the Akozon, Guagua, and Helix 30 cm rulers describe a gap or a bow past 15 cm. A line longer than the first leaf then swerves. Check the open edge against a known straight line before a cut.
Akozon and cersalt bullets mention an error of about ±0.02 mm. No accuracy class is printed. That line is a seller sentence. None of the twelve listings states Class I, II, or III.
Length decides the job. A 30 cm rule that folds to about 15 cm is a pencil case. The OX pack is 600 mm, four leaves of 150 mm, which is small layout. A 1 m or 2 m carpenter’s rule is the usual site length, and it is outside these twelve listings. The hinge has to open straight and stay there. Review patterns on the Akozon at £8.44 (3.8 from 172) and the Guagua at £3.79 (3.9 from 203) describe gaps at the fold, rules that are not straight, and snaps within days.
UK construction graduations are metric. The Helix J05100 at £4.44 states metric and imperial. Flexible sets in this batch state centimetres. A dual scale helps on inch stock and is easy to misread, so pick the edge you mean before you mark. Material follows the place: birch or engineering plastic for a site pocket, fibreglass if the work is wet, aluminium if it is hot.
Three typical situations, each with a recommendation from this comparison.
You need a 30 cm rule that folds into a pencil case and stays straight enough for school marks. The hinge is what fails in the reviews. The Helix 30 cm acrylic ruler is the top pick here at £4.44, with metric and imperial marks and 4.4 from 3,635 reviews. The same reviews report snaps and a gap past 15 cm, so check the open edge before a graph or a cut.
You need a rigid metric rule with joints that hold, usually at 1 m or 2 m. That length is outside this set. The OX Pro twin pack is the only site-style row: 600 mm, four 150 mm leaves, ABS, a brass hinge, a 0–180° swivel, £14.99, and 4.6 from 45 reviews. Use it when 600 mm is enough for the mark.
You want two named rules and you will check the open length in hand. The Helix Oxford pack is the best value at £5.49, with a metal material field and 4.6 from 237 reviews. The listing does not state the open length or the scale. Sixteen written reviews praise clear marks and also describe hinge snaps.
The twelve listings split into pencil-case folders and one 600 mm framing pack. The top pick is the Helix 30 cm acrylic ruler at £4.44, with 4.4 from 3,635 reviews, metric and imperial marks, and a hinge the reviews describe as snapping. The best value is the Helix Oxford two-pack at £5.49, with 4.6 from 237 reviews, if you can check the open length yourself. None of the twelve states an accuracy class, and a 1 m or 2 m site rule is outside this table.
Helix Oxford folding rule, pack of 2
£5.49 for two named rules, 4.6 from 237 reviews. The open length is not stated.
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.
Sources from the research digest. Shelf date 20 October 2026.
This page contains affiliate links. If you buy through them, we may earn a commission at no extra cost to you. Prices and reviews are taken from amazon.co.uk listings. This is not a laboratory test.
