Bath size guide: standard UK dimensions & how to measure
The standard UK bath is 1700mm long and 700mm wide. Common lengths run from 1500mm to 1800mm, and widths from 700mm to around 800mm. Those few numbers cover the large majority of baths sold in Britain, which makes a bath one of the more standardised things you'll buy for a bathroom.
But standardised doesn't mean foolproof: a bath is bulky, heavy, and expensive to get wrong, and the single most common ordering mistake is choosing a length that doesn't actually fit the space. This guide gives the standard dimensions, helps you choose between the two most common lengths, covers small-bathroom sizing, and walks the measuring method, so you order a bulky product once and order it right.
Standard UK bath sizes
The standard UK bath dimensions, by length:
| Length | Width | Best for |
|---|---|---|
| 1500mm | 700mm | Small bathrooms, ensuites |
| 1600mm | 700mm | Compact family bathrooms |
| 1700mm | 700–750mm | The UK standard; most family bathrooms |
| 1800mm | 800mm | Larger bathrooms, taller users |
Depth (the internal water depth) typically runs 500–550mm, though deep soaker tubs go further for a more immersive bathe. Width matters for comfort as much as length: a 700mm bath is standard, but an 800mm bath is noticeably roomier where the floor space allows it. When a product lists its size, it's given as length x width (for example 1700 x 700mm); always check both against your space, not just the length.
It helps to understand what each dimension does for you. Length determines whether you can stretch your legs out: 1700mm suits most adults, 1800mm suits taller users, and below 1500mm starts to feel cramped. Width affects how much room you have to move and whether two can share: 700mm is comfortable for one, 800mm gives welcome extra room. Depth is the dimension that decides how good the soak is, because it sets how much water sits above your body when you lie back; a deep bath gives a more immersive bathe than a shallow one of the same length. When you read a product's dimensions, read all three with these jobs in mind rather than focusing only on the headline length.
1500mm vs 1700mm
These are the two most common bath lengths, and the choice between them comes down to space and comfort:
- 1700mm is the UK standard, comfortable for most adults to stretch out in, and the size most bathrooms are designed around. Choose it wherever the space allows, because the extra length makes for a more comfortable soak.
- 1500mm is the compact choice for small bathrooms and ensuites where 1700mm won't fit. It's still comfortable for most adults, if a little snug for taller users, and a deep 1500mm soaker tub can give a more immersive bathe than a standard-depth 1700mm one.
The rule is simple: fit 1700mm if you can, drop to 1500mm (or a deep compact tub) when the space is genuinely tight. Always measure the clear wall run before deciding, because the difference between the two is exactly 200mm and that's often the difference between a bath fitting and not.
Consider who'll use the bath, too. For a tall household, 1700mm is the sensible minimum and 1800mm is worth the extra space if the room takes it, because a bath that's too short is uncomfortable every time it's used. For children and shorter adults, 1500mm is perfectly comfortable, and the extra floor space a shorter bath frees up can be more valuable in a small bathroom than length nobody needs. There's no virtue in a longer bath than the household will use, just as there's no comfort in one that's too short. Match the length to the people, then check it against the space.
Best size for a small bathroom
In a small bathroom, the best bath size isn't simply the smallest; it's the one that fits the space while still giving a usable bathe. Three approaches work:
- A compact straight bath at 1400–1500mm fits where a standard tub won't, on a usable straight wall run.
- A deep soaker tub trades length for depth, so even a short bath gives a proper, immersive soak by holding more water above the body.
- A corner or shower bath uses the room's geometry differently: a corner bath fits an unused corner, while a shower bath combines bath and shower in one footprint.
For the full small-bathroom approach, browse small & compact baths or read best baths for small bathrooms.
The mistake to avoid in a small bathroom is assuming you must sacrifice the soak to fit the room. You don't. A deep compact tub keeps a proper bathe in a short footprint by trading length for depth, and a shower bath gives you both a bath and a shower in the space a single fixture would take. The best small-bathroom size is the largest bath that fits comfortably with usable space around it, chosen in the form (compact straight, deep soaker, corner, or shower bath) that suits the room's shape. Measure first, then match the form to the space rather than simply buying the shortest tub you can find.
Allowing for access and the rest of the room
Fitting a bath isn't only about the wall it sits against; it's about the whole room working around it. Two things buyers often overlook:
- Getting the bath into the room. A bath is a single rigid item that has to travel from the front door, up any stairs, and round any corners to reach the bathroom. A 1700mm bath needs a clear path; tight stairwells and sharp landings occasionally make a long bath impossible to manoeuvre into an upstairs bathroom even when it fits the space perfectly. Check the route, not just the destination, before ordering a large tub.
- Living space around the bath. Once the bath is in, you need room to stand beside it to get in and out, to dry off, and to clean around it. A bath that fills the room wall-to-wall with no standing space beside it is technically a fit but an uncomfortable one. Leave a usable margin of floor space alongside the bath wherever the room allows.
Both of these are part of sizing a bath properly. The dimensions on the product page tell you whether the tub fits the wall; the access route and the surrounding space tell you whether it works in the room. Plan for both.
How to measure your space
Four measurements before you order:
- Length: the clear wall run. Measure wall-to-wall (or wall-to-obstruction) along the line the bath will sit. This is your maximum bath length; choose the nearest standard length down, allowing a little clearance for fitting and tiling.
- Width. Measure how far the bath can project into the room without blocking the door swing, the route to the toilet or basin, or a radiator. Standard width is 700mm; confirm it fits before assuming.
- Waste position. Note where the existing waste pipe sits relative to where the bath will go. A bath in a standard position usually lines up; a non-standard position may need the waste adjusting, which is far easier to plan before ordering than to fix on fitting day.
- Clearance. Check the door swing, any radiator, and the route past the bath. A bath that fits the wall run but fouls the door or leaves no room to pass isn't a workable fit. Measure the whole picture, not just the wall.
A worked example shows how this comes together. Say your bathroom has a clear wall run of 1,680mm where the bath will go, the room is 2,000mm deep, the waste pipe sits centrally, and the door opens inward at the foot end. The wall run rules out a 1700mm bath (it won't fit), so you size down to a 1600mm tub, leaving 80mm for fitting and tiling. At 700mm wide, the bath projects 700mm into the 2,000mm room, leaving 1,300mm of standing and circulation space, which is comfortable. The central waste lines up with a standard bath outlet, so no pipework moves. The door opens clear of the bath at the foot end. The answer: a 1600 x 700mm bath fits and works. That's the kind of five-minute check that turns an anxious bulky-item order into a confident one.
Write all four measurements down before browsing. Choosing the bath first and measuring second is how the wrong-size order happens; measure first, then shop within what fits.
Getting the size right is what turns a bulky, expensive, easy-to-get-wrong purchase into a low-risk one. The bath itself is standardised enough that once you know your numbers, the choice is straightforward: take your clear wall run, your width, your waste position, and your access route, and shop for the largest standard bath that fits all four with comfortable clearance. Do that and the bath arrives, fits, and installs without the costly surprise that catches out buyers who order on length alone. A few minutes with a tape measure is the best insurance there is against returning a bulky product.
Size & measuring FAQs
My bathroom wall is 1650mm. Can I fit a 1700mm bath?
No; a 1700mm bath won't fit a 1650mm run, and forcing it isn't possible with a rigid tub. Drop to a 1600mm bath, which leaves a small clearance for fitting and tiling, or a 1500mm if you want more margin. The 50mm shortfall is exactly the kind of measurement that catches buyers out, which is why measuring the clear wall run before choosing the length is the single most important step. Always size down to the nearest standard length that fits with clearance, never up.
What is a standard bath size in the UK?
The standard UK bath is 1700mm long and 700mm wide, with an internal water depth around 500–550mm. Common lengths run from 1500mm (compact) to 1800mm (large), and widths up to around 800mm. The 1700 x 700mm size is what most UK bathrooms are designed around and what most straight baths default to, so it's the safest assumption if you're planning a standard family bathroom, subject to measuring the actual space first.
The waste pipe isn't where the new bath needs it. What do I do?
Two options. If the bathroom is being substantially renovated anyway, the cleaner solution is to reposition the waste pipe to suit the new bath's outlet position, which a plumber can do during the rough-in stage. If you'd rather not move the pipework, choose a bath whose waste outlet lines up with the existing position, which may mean adjusting where the bath sits on the wall. Either way, check the waste position against the bath's outlet before ordering; it's the second most common fit problem after length.
Ready to find the right size? Browse baths by size, or return to the baths hub for the full range by type, style, and material.
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