Wheelchair Ramp Calculator - Part M & BS 8300 Gradient & Length
Calculate ramp length, gradient, landings, and handrail requirements to meet UK Building Regulations Part M and BS 8300.
Total vertical rise from ground to threshold level
Permanent ramps use 1:15 preferred gradient; temporary allows 1:12
Minimum 1200mm Part M, 1500mm recommended BS 8300
1:15 preferred for new permanent ramps
Required for rises over 300mm (both sides)
How We Calculate This
This calculator determines wheelchair ramp dimensions based on UK Building Regulations Approved Document M (Access to and use of buildings) and BS 8300:2018 (Design of an accessible and inclusive built environment).
Gradient calculation
The ramp going (horizontal length) is calculated as: Going = Rise x Gradient Ratio. For example, a 600mm rise at 1:15 gradient requires a 9000mm (9m) going.
Landing requirements
BS 8300 limits each flight of ramp to a maximum 500mm rise. Intermediate landings of at least 1200mm length are required between flights. Top and bottom landings must be at least 1200mm x 1500mm, clear of any door swing.
Handrail requirements
- Height: 900-1000mm from the ramp surface
- Diameter: 40-50mm circular cross-section
- Extension: 300mm beyond top and bottom of each flight
- Clearance: 50mm minimum from any wall or obstruction
Always consult with your local Building Control body and refer to the latest edition of Approved Document M for specific project requirements.
Frequently Asked Questions
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Last updated: March 2026
All calculations are estimates. Verify with your supplier.