What are the minimum dimensions for a wheelchair-accessible toilet?

A unisex wheelchair-accessible WC per Approved Document M requires a minimum room size of 1500mm x 2200mm. This allows space for a 1500mm diameter wheelchair turning circle, the WC pan, wash basin, and lateral transfer from wheelchair to WC. The door must have a minimum 950mm clear opening width.

What is a Doc M pack and what does it include?

A Doc M pack is a set of sanitaryware and fittings designed to meet Approved Document M requirements for accessible WCs. A standard pack includes: close-coupled WC pan with raised flush, wash basin, drop-down support rail, fixed support rails, back rest, mirror, shelves, coat hook, toilet roll holder, and alarm pull cord. Fittings are typically in contrasting colour (blue/white) for visually impaired users.

Why must accessible WC doors open outwards?

Doors to wheelchair-accessible WCs must open outwards or be sliding doors to ensure a wheelchair user is not trapped if they fall from their wheelchair inside the cubicle. An inward-opening door could block against a person on the floor, preventing rescue. The door must also be openable from outside in an emergency.

What is the difference between ambulant disabled and wheelchair-accessible WCs?

Ambulant disabled WCs are for people with mobility impairments who can walk (possibly with sticks or crutches) but do not use a wheelchair. They require a minimum 800mm x 1500mm cubicle with grab rails. Wheelchair-accessible WCs are larger (1500mm x 2200mm) with a turning circle and lateral transfer space. Building Regulations may require both types in non-domestic buildings.

How many accessible WCs are required in a commercial building?

Approved Document M Volume 2 requires at least one wheelchair-accessible unisex WC per floor in buildings other than dwellings, in addition to ambulant disabled cubicles within standard WC blocks. For large buildings, BS 8300 recommends an accessible WC within 40m travel distance of any point. The exact number depends on building use, occupancy, and total WC provision.

Accessible WC Calculator - Doc M Wheelchair Toilet Dimensions

Check whether your wheelchair-accessible toilet layout meets Approved Document M and BS 8300 requirements.

WC Type

Select the type of accessible toilet provision

Room Width

Internal clear width of the WC compartment

Room Length

Internal clear length of the WC compartment

Door Clear Opening Width

Effective clear width when door is open 90 degrees

Door Position

Position of door relative to the WC pan

Door Swing

Outward or sliding required for wheelchair accessible WCs

How We Calculate This

This calculator checks your proposed accessible toilet dimensions against the requirements of Approved Document M (Volume 2: Buildings other than dwellings) and BS 8300:2018.

Dimension checks

Room width: Minimum 1500mm for wheelchair accessible WC
Room length: Minimum 2200mm for wheelchair accessible WC
Turning circle: 1500mm diameter clear floor space
Door width: Minimum 950mm effective clear opening

Grab rail positions

Grab rails must be positioned per the standard Doc M layout. Drop-down rails are provided on the transfer side (the side the wheelchair user approaches from). Fixed rails on the opposite side. All rails at 680mm above finished floor level, 320mm from the centre line of the WC pan.

WC types assessed

Unisex Accessible WC: Full wheelchair accessible, Doc M compliant (1500 x 2200mm)
Ambulant Disabled WC: For ambulant users with mobility aids (800 x 1500mm)
Enlarged Cubicle: Larger than standard, for mobility aid users (1200 x 1500mm)

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.