Ramp Calculator — Wheelchair Access & Gradient

This calculator determines the correct ramp design based on UK Building Regulations Part M (Access to and use of buildings) and Part K (Protection from falling). It automatically selects the appropriate gradient based on the height rise.

Part M gradient requirements (AD M Vol 2 Table 2)

• Up to 166mm rise per flight: Maximum gradient 1:12 (max 2m going)
• Up to 333mm rise per flight: Maximum gradient 1:15 (max 5m going)
• Up to 500mm rise per flight: Maximum gradient 1:20 (max 10m going)

Key requirements

• Minimum width: 1200mm (1500mm preferred for wheelchair passing)
• Landings: Top, bottom, and every 10m of ramp length (min 1200x1200mm)
• Handrails: Both sides at 900-1000mm height, extending 300mm past each end
• Tactile paving: Corduroy hazard warning at top and bottom
• Surface: Must be firm, durable and slip-resistant

The ramp length is calculated as: height difference x gradient ratio. For example, a 150mm rise at 1:12 gradient = 0.15 x 12 = 1.8m ramp length. A 600mm rise exceeds the 333mm per-flight cap, so 1:20 is applied and the ramp is split into multiple flights with landings.