Back to MAIN MENU.


BS:8300-2018 recommends gradients and details for slopes and ramp design. Slopes are gradients between 1 in 60 up to 1 in 20. They should have level landings not less than 1500mm long for the full width of the route for every 500mm rise in height and at the top and bottom of the slope, clear of any door swings. The surface of the slope should contrast visually with any loandings.

Ramps should have a 100mm raised edge at the side drops to stop wheels slipping over and to provide a tapping edge for cane users. There should be a 1500mm level resting space outside the swing of any doors at the top. This is so that a wheelchair user does not roll backwards while trying to open a door.

Designs should assume that disabled people will want their own, independent access, without needing to rely on assistance at doors etc.

An alternative route up steps should be provided where possible as some people may have difficulty in using ramps. If only one solution is possible, it should be a ramp.

Ramps and steps should have handrails on both sides so that they can be used by people with a mobility problem on one side. Handrails should be easy to grip. The handrail is not the same as the top of a balustrade, which is required to protect users from falling down a drop. In some positions it may be necessary to provide a handrail and a balustrade. Handrails should not be in unprotected metal, as they could be cold to touch. This can be particularly difficult for people with limited feeling in their hands or fingers.


Long ramps need level resting places where wheelchair users can take a breather. Others may need this too. If there is a space, something to sit on would be useful for people with strength, stamina or mobility problems.


Gradients can be calculated by measuring the height and the horizontal length of each section. These should be in the same units eg. millimetres. The length is then divided by the height. The gradient is expressed as 1 in (the length/ the height)

Sometimes it is only possible to measure up the ramp instead of along the horizontal. Then a spirit level and more complex calculation is needed, unless an inclinometer is available.


Gradients take extra energy to get up and can make speed control difficult when going down. A steep incline can put the chair in danger of tipping backwards or forwards. Many users cannot lean forward or adjust their balance to allow for a gradient.

A cross fall can similarly put a wheelchair user at risk and may also affect the steering, particularly on a manually propelled chair. Crossfalls should not exceed 1 in 50.


Gradients of 1 in 20 or less are counted as virtually level. Gradients up to 1 in 15 can be negotiated with a little difficulty. Between 1 in 15 and 1 in 12 it is getting noticably harder, particularly if the incline is long. Above 1 in 12 there is a very real potential for tipping over and such gradients are outside the recommendations. There is a table of ramp gradients in BS:8300. 1 in 20 gradients should not exceed 10m in length without a landing, 1 in 15 should not exceed 5m and 1 in 12 should not exceed 2m.


Rough surfaces make steering difficult, particularly on slopes. They will also be uncomfortable for the wheelchair user. This can be severe, particularly for people with spinal conditions. The tactile paving necessary for people with visual impairments can cause discomfort and difficulties for wheelchair users. However, a non slip surface is essential, particularly for people with walking mobility problems.


The surface width of a ramp between walls, upstands or kerbs should not be less than 1500mm.