Bath sizes in the UK: what is standard and which size fits your room?

The table below shows the sizes you will see most often from UK suppliers. Exact dimensions vary slightly between brands, so always check the specification sheet of the model you choose rather than relying on the nominal size.

Measure the gap between the walls at the height of the bath rim, not at floor level. Walls are rarely perfectly square, and older houses in particular can lose several millimetres over the length of a bath.

Take the measurement at both ends and in the middle, and work from the smallest figure. If the old bath is still in, measure it too, including any lip that sits under the tiles.

Check the height from the floor to the underside of any window sill, and note where the waste and taps are. A bath with the taps at the opposite end, or a different waste position, can mean moving pipework.

Finally, measure the route into the room. Doorways, landings and tight stair turns decide whether a long or freestanding bath can physically be carried in.

Shower baths are usually the same length as a standard bath but wider at one end to give more room for showering, often shaped as a P or L. They suit rooms where a separate shower will not fit.

Corner baths take up more floor area than their length suggests, so they suit larger, squarer rooms rather than the typical narrow bathroom.

Freestanding baths need space around them for cleaning and for the look to work. Allow room on each side and plan the waste and tap position under the floor before the new floor goes down.

Going shorter can free up space for a larger basin, a storage unit or a wider doorway. Going longer or wider can make bathing more comfortable if the room allows it. Either way, the tiles around the bath usually need replacing, because the old tile line will not match.

If nobody in the house uses the bath, it may be worth asking whether you need one at all. Replacing a bath with a shower is one of the most common changes we make, and our guide on that covers what is involved.

Whatever the size, a bath needs to be level, fully supported on its feet or frame, and fixed so it does not move when someone steps in. Acrylic baths in particular flex if the support is poor, which breaks the sealant and lets water behind the panel.

We fill the bath with water before the final silicone seal is applied, so the seal is made at the point where the bath sits lowest. That simple step is one of the best ways to stop the joint cracking later.