12 percent: steeper than most driveways
12% is 6.84°, about 1 in 8.33. It is above the 5 to 10% most driveways sit in and about 1.4 times the 1:12 ramp limit, so it is a slope for a bank, a path with steps, or a short drive where there is no room for less.
It rises 1.44 inches per foot. A 24 inch rise takes only 16.7 feet of run at this grade.
Over a 50 foot drive that is a climb of 6 feet.
12% slope: rise over a distance
A 12% slope rises 12 feet in every 100 feet of level distance.
| Run (level distance) | Rise in inches | Rise in feet | Length along the slope |
|---|---|---|---|
| 1 ft | 1.44 in | 0.12 ft | 1.01 ft |
| 10 ft | 14.4 in | 1.2 ft | 10.07 ft |
| 20 ft | 28.8 in | 2.4 ft | 20.14 ft |
| 50 ft | 72 in | 6 ft | 50.36 ft |
| 100 ft | 144 in | 12 ft | 100.72 ft |
Worked example
12 ÷ 100 = 0.12. The angle is the arctangent of that: arctan(0.12) = 6.84°. As a ratio, 100 ÷ 12 = 8.33, so the slope is 1 in 8.33. Per foot, 0.12 × 12 = 1.44 inches.
Nearby grades in degrees
| Grade | Angle | Ratio | Rise per foot |
|---|---|---|---|
| 5% | 2.86° | 1 in 20 | 0.6 in |
| 8.33% | 4.76° | 1 in 12 | 1 in |
| 10% | 5.71° | 1 in 10 | 1.2 in |
| 12% | 6.84° | 1 in 8.33 | 1.44 in |
| 15% | 8.53° | 1 in 6.67 | 1.8 in |
| 20% | 11.31° | 1 in 5 | 2.4 in |
| 25% | 14.04° | 1 in 4 | 3 in |
For any other rise, run or grade use the slope and grade calculator. The guide slope and grade for drainage and ramps covers how much fall each job needs.
Want to change anything else? The calculator above is the full Slope and Grade Calculator: edit any number and the results update instantly.
Tools & materials for this project
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Frequently asked questions
What is a 12 percent slope in degrees?
6.84 degrees. Divide the percent by 100 and take the arctangent: arctan(0.12) = 6.84°.
Is a 12 percent slope 12 degrees?
No. A 12% slope is 6.84°. Percent is rise over run times 100, and the angle is the arctangent of rise over run, so the two numbers only look alike.
How much does a 12% slope rise per foot?
1.44 inches for every foot of run, which is 14.4 inches over 10 feet and 12 feet over 100 feet.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.