Ramp Calculator Toolkit for Architects and Designers

Welcome to our Ramp Calculator Toolkit, designed to help architects, designers, accessibility consultants, and anyone working with ramps comply with Part M of UK Building Regulations.

This toolkit includes three simple, powerful tools:

  • Ramp Height Calculator
  • Ramp Length Calculator
  • Ramp Gradient Reference Tool

Ramp Length Calculator

What it does:
Enter the vertical height (rise) you need to overcome, and this calculator will output the required ramp lengthsfor all gradients from 1:12 to 1:20.

When to use it:
Ideal for early-stage planning when you know the floor height difference and want to find out how long a ramp you’ll need depending on your gradient choice.

Example scenarios:

  • You’re designing a building with a 300mm floor level change and want to compare how long the ramp would be at different gradients.
  • You’re planning a modular ramp system and want to see if you can fit the required length within the available space.

Ramp Length Calculator

Your results will appear here.

Ramp Rise Calculator

What it does:
Input your ramp length and a gradient, and the calculator tells you the maximum allowable rise (height)of your ramp.

When to use it:
Use this tool when you’re planning how high your ramp can go based on space constraints or gradient requirements. This is especially useful when retrofitting ramps into existing spaces.

Example scenarios:

  • You’re installing a wheelchair ramp in a small garden and need to check how high a 4m ramp can go using a 1:15 slope.
  • You’re working on an existing project and need to understand the constraints you are working within.

Ramp Rise Calculator

Your results will appear here.

Ramp Gradient Reference Tool

What it does:
Helps you choose a suitable ramp gradient based on your desired rise and run, or vice versa.

When to use it:
Useful for comparing gradients or validating your design decisions against Approved Document M requirements.

Example scenarios:

  • You’re choosing between 1:12 and 1:15 for a ramp and want to confirm the implications of each.
  • You need to present accessible design options to a client and show how each gradient affects length and usability.

Ramp Gradient Calculator

Your result will appear here.

Part M Ramp Guidance

The following notes apply to Approved Document Part M – Dwellings. For full information and guidance refer to Part M.

Gradient range

From 1:20 (shallowest, approx. 5%) to 1:12 (steepest, approx. 8.3%).

Maximum flight length at each gradient

1:20 → 10 m
1:19 → 9 m
1:18 → 8 m
1:17 → 7 m
1:16 → 6 m
1:15 → 5 m
1:14 → 4 m
1:13 → 3 m
1:12 → 2 m

Clear width

Private ramps: minimum 900 mm clear.

Communal ramps: minimum 1200 mm clear.

Landings

Every flight must have a top and bottom landing.

Intermediate landings are required between flights and at any change of direction.

Each landing must be at least 1200 mm long, clear of any door or gate swing.

Approach routes

Should be step‑free, safe and convenient, adopting the shallowest gradient reasonably achievable.

If the overall rise is 300 mm or more, a stepped alternative route meeting paragraph 2.11 must also be provided.

Notes

A site‑wide gradient of 1:15 will normally need a series of 1:12 ramps with intervening landings.

To check rise: gradient × length of flight. E.g. 1/20 × 10 m = 0.5 m (500 mm).