What is the grade percentage for ramp inclination?

What is the grade percentage for ramp inclination?

• A. 6%
• B. 8.3%
• C. 9%
• D. 12%

Answer: (B)

Grade percentage is the rise of the ramp divided by its run, times 100. For accessibility, a common standard is a rise of 1 unit for every 12 units of run, which is 1/12 = 0.0833, or about 8.33%. So the ramp inclination is 8.3%. So other percentages correspond to different rise/run ratios: 6% would be a shallower 1:16.7, 9% would be 1:11.1, and 12% would be 1:8.3, which are steeper or flatter than the typical accessible slope. The 8.3% figure reflects the 1:12 rule.

Grade percentage is the rise of the ramp divided by its run, times 100. For accessibility, a common standard is a rise of 1 unit for every 12 units of run, which is 1/12 = 0.0833, or about 8.33%. So the ramp inclination is 8.3%.

So other percentages correspond to different rise/run ratios: 6% would be a shallower 1:16.7, 9% would be 1:11.1, and 12% would be 1:8.3, which are steeper or flatter than the typical accessible slope. The 8.3% figure reflects the 1:12 rule.