50 percent: a 6/12 roof
50% is 26.57°, 1 up for every 2 along, not 45°. It rises 6 inches per foot, which is a 6/12 roof pitch.
The surface is noticeably longer than the plan: 100 feet of run is 111.80 feet along the slope, so a roof or a bank at this grade has about 12% more surface than its footprint.
Over a 14 foot run a roof at this pitch rises 7 feet.
50% slope: rise over a distance
A 50% slope rises 50 feet in every 100 feet of level distance.
| Run (level distance) | Rise in inches | Rise in feet | Length along the slope |
|---|---|---|---|
| 1 ft | 6 in | 0.5 ft | 1.12 ft |
| 10 ft | 60 in | 5 ft | 11.18 ft |
| 20 ft | 120 in | 10 ft | 22.36 ft |
| 50 ft | 300 in | 25 ft | 55.90 ft |
| 100 ft | 600 in | 50 ft | 111.80 ft |
Worked example
50 ÷ 100 = 0.5. The angle is the arctangent of that: arctan(0.5) = 26.57°. As a ratio, 100 ÷ 50 = 2, so the slope is 1 in 2. Per foot, 0.5 × 12 = 6 inches.
Nearby grades in degrees
| Grade | Angle | Ratio | Rise per foot |
|---|---|---|---|
| 25% | 14.04° | 1 in 4 | 3 in |
| 30% | 16.70° | 1 in 3.33 | 3.6 in |
| 33% | 18.26° | 1 in 3.03 | 3.96 in |
| 50% | 26.57° | 1 in 2 | 6 in |
| 100% | 45.00° | 1 in 1 | 12 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 50 percent slope in degrees?
26.57 degrees. Divide the percent by 100 and take the arctangent: arctan(0.5) = 26.57°.
Is a 50 percent slope 45 degrees?
No. A 50% slope is 26.57°. A 45° slope is a 100% grade, where the rise equals the run.
How much does a 50% slope rise per foot?
6 inches for every foot of run, which is 60 inches over 10 feet and 50 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.