300 litre water butt: what to check before you buy

Updated: 22 October 2026

You have a plastic downpipe and a gap beside the house, and a search for a 300 litre water butt has already mixed the sizes. One title says 380 litres while the specification line says 350.

You have a plastic downpipe and a gap beside the house, and a search for a 300 litre water butt has already mixed the sizes. One title says 380 litres while the specification line says 350. Others are 250 litres, 210 litres, or a decorative 120. You need the litres you can trust, the footprint that fits, and a straight answer on the stand and the diverter. The 300 litre water butt comparison is the amazon.co.uk set we read on 20 October 2026, from £41.99 to £124.99. A purchase through those links may earn us a commission at no extra cost to you. This page does not name a winner.

Our top picks

Badge	Product	Stated capacity	Footprint	Stand and diverter	Note	Price	Offer
Best overall	Original Organics Original Organics (STA-GN355BLK)	250 litres	Width printed as 540 cm	Stand and diverter in the title	8.1	about £79.99	View offer
Best value	Strata Strata (Fuzz01)	210 litres	60 × 60 × 90 cm	Stand extra; no diverter	8.2	about £49.99	View offer
	Ward Ward (GN340)	250 litres	54 × 54 × 121 cm	Stand and diverter extra	8.8	about £64.99	View offer

Best overall

Original Organics Original Organics (STA-GN355BLK)

8.1/10about £79.99

View offer

Best value

Strata Strata (Fuzz01)

8.2/10about £49.99

View offer

Rank 3

Ward Ward (GN340)

8.8/10about £64.99

View offer

On this page

1.What 300 litres means on this search
2.Footprint, height, and a full butt
3.Tap, lid, stand, and diverter
4.Downpipe, overflow, and pressure
5.What not to assume

What 300 litres means on this search

On this search, 300 litres is a size band, not a promise that every result holds 300 litres. In the listings saved on 20 October 2026, the Ward, Original Organics, and Bowers butts are stated at 250 litres. The Strata butt is 210 litres. Treat the specification line as the working volume. The RHS notes that 1 mm of rain on 1 square metre of roof is 1 litre before losses, and about three quarters of that after losses is a rule of thumb.

Footprint, height, and a full butt

Volume does not tell you the depth against the wall. The Ward GN340 is listed at 54 × 54 × 121 cm and about 6 kg empty. The 210 litre Strata is 60 × 60 × 90 cm. A full 250 to 300 litre butt is about 250 to 300 kg of water plus the shell. The RHS wants a firm, level stand. One Original Organics line prints a width of 540 cm. Do not use that figure as the depth of the path.

Testsieger

Original Organics Original Organics (STA-GN355BLK)

8.1/10about £79.99

View offer

Tap, lid, stand, and diverter

The tap, the lid, the stand, and the diverter are four separate objects. “Kit” in a title is not a parts list. The Ward arrives with a loose tap and a clip-on lid. It fits stand GN175 or GN176, and those stands are not in the box. Reviewers say a watering can will not reach the bottom tap until the butt is raised. Original Organics, at £79.99, is the rigid listing whose title names a tap, a lid, a stand, and a diverter together.

Downpipe, overflow, and pressure

Most plastic downpipes on UK houses are 68 mm round or 65 mm square. Cast iron is a different job. Measure yours before you order the fitting. A diverter sends roof water into the butt and, when the butt is full, lets the rest continue down the pipe to the drain. If the overflow sheets against the wall, you have aimed hundreds of litres at the brickwork. Where to cut is on the how to install a water butt page. Gravity from the tap fills a watering can. It does not run a hose across a lawn.

What not to assume

Do not treat a frost-proof bullet as a winter test. Nothing in this set was frozen in a lab. Ice expands, so empty the butt and leave the tap open, or store a folding barrel where it will not freeze. Budget the butt, then a stand if the tap must clear a can, then a diverter for 68 mm or 65 mm plastic, then a filter if none is listed. A rigid slimline that stays by the pipe, or a barrel you pack flat, is the slimline versus collapsible split.

Common questions

Is a water butt sold as 300 litres actually 300 litres?

Often it is not. In this set, saved on 20 October 2026, the common rigid size is 250 litres, one butt is 210 litres, and a folding title says 380 litres while its specification line says 350. Read the specification line. If a listing also prints 53 gallons beside a 200 litre title, that figure belongs to the listing. We did not convert it into a new capacity.

What footprint does a 250 litre slimline need?

The Ward GN340 is listed at 54 × 54 × 121 cm. The Bowers 250 litre butt is listed at 121 × 50 × 54 cm. You also need room for a stand, the lid, and a watering can. Measure the side return. Ignore a printed width of 540 cm. That figure cannot be the depth of a wall-side tank.

Do I need a stand so a watering can fits?

You need one when the tap sits at the bottom. Ward buyers say a can will not reach the tap until the butt is on a base, and stand GN175 or GN176 is sold separately. A basic stand is often about £10 to £20, as a rule of thumb, not a current price for a named product. Confirm a kit stand is in the parcel before you cut the downpipe.

Does the box include the diverter?

Sometimes the title says so, and sometimes the box does not. The Ward does not include a diverter, and reviewers say the connector in the video is extra. Original Organics names one in the title. Bowers does not include a downpipe kit. Match the fitting to 68 mm round or 65 mm square plastic, and measure your pipe first.

Will a hose work from the tap without a pump?

No. The tap is a gravity outlet for a watering can. The RHS says a hose from a water butt needs a pump. A middle tap can be weaker still. Reviewers of one folding barrel here describe a trickle even when the tank is full. Dip a can and you can skip the pump. Reaching a far bed is when you need it.

Can I drink water from a water butt?

No. Roof rainwater is not drinking water, and it is not for washing food. A seller line about storing drinking water after a clean does not change the gutter. Keep stored rain off seedlings, which is RHS advice. A lockable-lid bullet is not a child lock either. RoSPA says cover or fence off butts, because a young child can drown in very little water.

Best water butt in this set