Vanity Unit Size Guide: Width, Depth, Height and How to Measure
Choosing the right vanity unit starts with the measurements.
Before you decide on colour, finish, handles or basin style, you need to know what size will actually work in your bathroom. A vanity unit needs to fit the wall, leave enough standing space, clear the door swing and connect properly to the plumbing.
Vanity units are available in a wide range of sizes, from compact 300mm cloakroom units to large 1800mm double basin designs. This guide explains the key dimensions, how to measure your space and what to check before ordering.
Standard Vanity Unit Sizes
Vanity units vary by product, but most fall into common size ranges.
Widths typically run from around 300mm to 1800mm. Depths are usually around 300mm to 500mm from front to back. Heights are often around 800mm to 900mm to the top of the basin.
The right size depends on the room, the wall space and how the bathroom is used.
Vanity Unit Widths by Room Type
Cloakrooms and Downstairs Toilets
Cloakrooms usually suit vanity units around 300mm to 500mm wide.
These compact units are designed for handwashing and small amounts of storage. In very tight rooms, a slim-depth or wall-hung design can help keep the space feeling more open.
Small Ensuites
Small ensuites often suit vanity units around 500mm to 600mm wide.
This gives you a more usable basin than a tiny cloakroom unit while still keeping the footprint compact. Check the depth carefully, especially if the ensuite is narrow.
Family Bathrooms
Most standard family bathrooms suit vanity units around 600mm to 800mm wide.
This size range provides a comfortable basin and useful storage without taking over the room. A 600mm vanity is a good starting point for many UK bathrooms, while 700mm or 800mm options give you more storage where space allows.
Master Ensuites
Master ensuites often suit vanity units around 700mm to 1000mm wide.
This gives the basin area more presence and offers extra drawer or cupboard space. If two people regularly use the room at the same time, you may want to consider a larger double basin design.
Double Basin Bathrooms
Double basin vanity units usually start from around 1200mm wide, but 1400mm or more is more comfortable.
A 1200mm double vanity can work, but it may feel tight. From 1400mm to 1800mm, there is more room for two basins, better spacing and more useful storage underneath.
Vanity Unit Depths
Depth is just as important as width, especially in small bathrooms.
Most standard vanity units are around 300mm to 500mm deep. Wider depths can offer more storage and a larger basin, but they also project further into the room.
In cloakrooms and narrow ensuites, a standard-depth vanity can make the room feel cramped. A short-projection vanity may be a better choice where space in front of the basin is limited.
Short-Projection Vanity Units
Short-projection vanity units are shallower from front to back.
They are useful in narrow cloakrooms where the wall width is available but the room depth is tight. These units help preserve standing space and reduce the chance of blocking the door swing or walkway.
Always check the full projection, including the basin, not just the cabinet depth.
Vanity Unit Heights
Most vanity units are around 800mm to 900mm high to the top of the basin.
This height range is designed to be comfortable for most adults when washing hands, brushing teeth or using the basin. The exact height may vary depending on the cabinet and basin type.
Countertop basins can add height above the surface, so check the overall height carefully. A unit that looks standard on paper may feel taller once the basin is included.
Wall-Hung Vanity Heights
Wall-hung vanity units can often be fitted at a chosen height within reason.
This gives your installer some flexibility to set the basin at a comfortable level. However, plumbing positions, wall strength and product instructions still need to be considered.
Floorstanding Vanity Heights
Floorstanding and freestanding vanity units have a fixed height.
Because they sit on the floor, the basin height is set by the cabinet and basin design. Always check the total height before ordering, especially if the users are particularly tall or short.
How to Measure for a Vanity Unit
Before choosing a vanity, take a few key measurements.
Write them down before browsing product pages. It is much easier to shop within the right size range than to fall in love with a unit and then discover it will not fit.
Measure the Available Wall Width
Measure the clear wall space where the vanity will sit.
Take measurements between fixed points such as corners, soil pipes, shelves, window reveals or boxing. If the wall is between two obstructions, do not assume the full distance is usable.
It is sensible to leave a small amount of clearance either side of the unit rather than fitting it tightly edge to edge. This allows for wall imperfections, installation tolerance and a cleaner finished look.
Measure the Room Depth
Measure from the vanity wall out into the room.
Check how much space will remain in front of the basin once the unit is fitted. You need enough room to stand comfortably and use the basin without feeling squeezed.
In small rooms, room depth can be more important than wall width.
Check the Door Swing
Open the bathroom door fully and check where it moves through the room.
The vanity, basin, handles and open drawers must not sit in the door swing. This is especially important in cloakrooms and downstairs WCs, where the door often opens close to the basin area.
Marking the door swing on the floor with masking tape can help you see the usable space more clearly.
Check Drawer and Door Clearance
Make sure drawers and cupboard doors can open properly.
A vanity might fit against the wall but still be awkward if the drawers hit the toilet, radiator, shower screen or bathroom door. If choosing a drawer unit, measure the space in front as well as the width.
Measure the Plumbing Position
Check where the water supply and waste pipe are located.
Measure the position of the waste pipe from a fixed point, such as the corner of the room or the edge of a wall. Note whether the waste exits through the wall or floor.
Compare these measurements with the product specification. If the waste pipe does not line up closely with the basin position, speak to your plumber before ordering.
Plumbing Clearance and Basin Projection
Plumbing is one of the most important checks when choosing a vanity unit.
Basin Projection
The basin may project further than the cabinet.
This is particularly common with some countertop basin designs, where the basin sits on top of the vanity surface. Always check the full depth of the unit including the basin and any tap projection.
Bottle Trap Clearance
The bottle trap sits below the basin and connects to the waste pipe.
It needs enough room within the cabinet or behind the unit. This is especially important with shallow, low-height or drawer-based vanities, where internal space may be limited.
Check the product specification and ask your installer if you are unsure.
Waste Pipe Offset
A small offset between the basin waste and the wall waste can often be managed by a plumber.
A larger offset may need pipework to be adjusted or the vanity position to change. If your existing waste pipe is not close to where the basin will sit, confirm the options before ordering.
Planning Vanity Storage
Size is not only about external dimensions. The internal storage layout matters too.
A wider cabinet does not always mean better storage if the drawers are shallow or the pipework takes up too much space.
Daily Storage
Toothbrushes, toothpaste, skincare, razors and small toiletries are best stored in easy-access drawers.
Top drawers are particularly useful because you can reach them without bending down.
Larger Items
Hair tools, cleaning products, larger bottles and spare toiletries need deeper drawers or cupboard space.
If these are important to you, check whether the vanity has full-depth drawers, shelves or a cupboard section.
Family Bathroom Storage
In a family bathroom, a mixed layout can be useful.
Drawers can hold everyday items, while cupboards can store bulkier products and cleaning supplies. Choose the internal layout based on what you actually need to store, not just how the unit looks from the outside.
When Standard Vanity Sizes Do Not Fit
Most bathrooms can be fitted with a standard vanity size, but not all.
You may have an awkward wall width, a sloped ceiling, a chimney breast, boxed pipework or a door swing that makes standard units difficult. In these situations, forcing a standard size can leave gaps, block movement or make the installation look compromised.
When to Consider Bespoke
A bespoke or made-to-measure vanity unit can be built to suit your exact space.
This can be useful if your wall falls between standard sizes, if the room has unusual geometry or if you need a particular height, depth or basin position.
Bespoke usually costs more and takes longer than ready-made furniture, so it is best used when it solves a real fit problem.
Measuring Checklist Before You Order
Before ordering a vanity unit, check:
The available wall width.
The room depth from the wall to the opposite side or nearest obstruction.
The door swing.
The space needed for drawers and cupboard doors to open.
The waste pipe and water supply positions.
The full basin projection.
The total height to the top of the basin.
Any skirting, boxing, radiators, shelves or window reveals.
These checks will help you avoid the most common fitting problems.
Vanity Unit Size and Measuring FAQs
I have exactly 700mm of wall. What size vanity should I get?
A 600mm vanity will usually be the safer choice. Leaving some clearance either side helps with installation, wall imperfections and the finished look. A 700mm vanity in exactly 700mm of wall space may feel too tight and may be harder to fit neatly.
What happens if the waste pipe does not line up with the basin?
A small offset can often be managed with pipework, but a larger offset may need the waste pipe moved or a different vanity position. Check with your plumber before ordering if the waste pipe is not close to the basin position.
What depth vanity unit do I need for a cloakroom?
Many cloakrooms need a slim-depth or short-projection vanity. If the room is narrow, check how much standing space remains in front of the unit once fitted. Always measure the full projection including the basin.
What height should a vanity unit be?
Most vanity units are around 800mm to 900mm high to the top of the basin. This suits most adults. Countertop basins can increase the total height, so check the full product dimensions.
Do wall-hung vanity units have adjustable height?
They can often be fitted at a chosen height within the product and plumbing limits. Your installer will need to follow the fitting instructions and check wall strength, pipework and basin height.
What should I do if no standard vanity size fits?
If no standard size works properly, consider a bespoke or made-to-measure vanity unit. This can be useful for awkward walls, sloped ceilings, boxed pipework, alcoves and non-standard widths.
Find the Right Vanity Unit Size at Plumbworld
Measuring properly is the best way to choose a vanity unit that fits well and works every day.
Start with the wall width, then check depth, height, door swing, plumbing and storage. Choose a compact vanity for a cloakroom, a 600mm to 800mm unit for most family bathrooms or a wider vanity for a larger bathroom or double basin layout.
Browse Plumbworld’s vanity units by size, cloakroom vanity units, large vanity units, double basin vanity units and bespoke UK-made vanity units to find the right fit for your space.