Ramp Sizing Guide 1. Select your step height from the left hand column. 2. Using the key below estimate what gradient is most suitable. 3. Follow the chart to the bottom, length of ramp required is shown in red. Gradient Key: 1:15 Gradient - Public Access 1:12 Gradient - Recommended for unassisted wheelchair access 1:6 Gradient - For manual and power chairs with assistance 1:4 For loading and unloading unoccupied chairs and scooters. Step Height Gradient 3" / 76mm 1:8 1:9 1:11 1:12 1:13 1:15 1:18 1:20 1:22 1:24 1:26 1:28 1:34 4" / 102mm 1:6 1:7 1:8 1:9 1:10 1:11 1:13 1:15 1:16 1:18 1:19 1:21 1:25 5" / 127mm 1:5 1:6 1:6 1:7 1:8 1:9 1:11 1:12 1:13 1:14 1:16 1:17 1:20 6" / 152mm 1:4 1:5 1:5 1:6 1:7 1:8 1:9 1:10 1:11 1:12 1:13 1:14 1:17 7" / 178 mm   1:4 1:5 1:5 1:6 1:7 1:8 1:9 1:9 1:10 1:11 1:12 1:15 8" / 203mm     1:4 1:4 1:5 1:6 1:7 1:8 1:8 1:9 1:10 1:11 1:13 9" / 229mm         1:4 1:5 1:6 1:7 1:7 1:8 1:8 1:9 1:11 10" / 254mm           1:5 1:5 1:6 1:7 1:7 1:7 1:8 1:10 11" / 279mm           1:4 1:5 1:5 1:6 1:7 1:7 1:8 1:9 12" / 305mm             1:4 1:5 1:6 1:6 1:6 1:7 1:8 13" / 330mm             1:4 1:5 1:5 1:6 1:6 1:7 1:8 14" / 356mm               1:4 1:5 1:5 1:6 1:6 1:7 15" / 381mm               1:4 1:4 1:5 1:5 1:6 1:7 16" / 406mm                 1:4 1:4 1:5 1:5 1:6 18" / 457mm                   1:4 1:4 1:5 1:6 Length of Ramp Required (mm) 610 710 810 925 1015 1170 1370 1525 1680 1830 1980 2135 2590   * To be used as a guide only * Contact our sales team for further information on this product.