Understanding Bath Sizes

Close up product lifestyle image of BC Designs Dinkee 1500mm Acrylic Freestanding Bath
Published: 16th November 2011
Author: James Roberts

If you are on the hunt for a new bath, either to replace one that you already have or as part of a new development, you will have come across the term standard UK bath size. What if, however, you are looking for something outside of this definition, perhaps a small bath or even a large bath.  Knowing a little more about bath dimensions should hopefully make the decision making a little easier when trying to make the right purchase.

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How Long Is A Bathtub?

When the imperial system was in use, the standard bath size in the UK was 5’6” in length. With the introduction of the metric system the current standard bath size in the UK is 1700mm in length and 700mm wide. This was seen as a direct replacement for the imperial standard sized bath.

What is the Standard Bath Size?

When it comes to look at baths in simple terms, the standard bath sizes are:

Standard UK Bath Sizes(mm):

  • Standard bath size – 1700mm long x 700mm wide
  • Small bath – 1400mm long x 700mm wide
  • Compact bath – 1200mm long x 700mm wide
  • Large bath – 1800mm long x and upwards

As it is commonly accepted that the standard bath width is 700mm, a wide bath is considered to be any bath with a diameter of 800mm and above. Large baths with dimensions over 1800mm in length and over 800mm wide tend to be freestanding baths. The above is a general guideline to bath sizes in the UK but what if the bath length you are looking for does not fit neatly into common specifications?

How to Replace A Bath

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A common query that we hear at Sanctuary Bathrooms is: “We are looking to replace a bath that currently fits wall to wall in our bathroom. On measuring the length of the bath, it measures exactly 1685mm. However, on looking at available baths, it’s very difficult to find bath lengths of this precise size. What shall we do?”

This is a common problem and the solution is maybe easier than you think. Often times when people measure up for a bath, they measure from wall to wall. This particular measurement can be skewed somewhat if the walls are tiled at either end or both ends. If the walls are tiled, then the bath actually sits slightly underneath the tiles, so the measured length from tiled wall to tiled wall will be different to the length measured after the removal of the tiles. Therefore, in response to our query, if our customer measured the tiled wall to tiled wall and the length was 1685mm, they may well find that the untiled wall to untiled wall measurement is much closer to 1700mm.

As long as the difference between the two measurements isn't large, or the tolerance level isn’t vast such as anywhere from 10mm–30mm, then substituting a 1700mm bath for a 1685mm bath shouldn’t cause too many problems and will give you more scope in terms of choice of baths.

Replacing A Bathtub

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This guideline isn’t set in stone, however. Do check with a professional bathroom fitter as not all instances will fit this scenario. There may be times when after having removed all tiles the wall to wall length is still at odds with the bath dimensions. This may call for a case of channelling out some of the wall. Again, a professional bathroom fitter will be able to advise you on this.

If after all of this, you still are having issues finding the bath size to fit your space, and you definitely do not want to undertake any structural work then keep looking. There are bath sizes to accommodate all spaces. Granted, you will have to look a little harder but eventually your hard work will pay off and you will be rewarded with the perfect bath for you for the space that you have.