Slope Calculator: Convert Between Degrees, Gradient, and Grade
Convert slopes pitch between degrees, gradients and grades.
Slope or gradient of a line describes the direction and the steepness of a line. Slope can be expressed in angles, gradients or grades.
Slope expressed as Angle
Sangle = tan-1(y / x) (1)
where
Sangle = angle (rad, degrees (°))
x = horizontal run (m, ft ..)
y = vertical rise (m, ft ...)
Example - Slope as Angle
Slope as angle for an elevation of 1 m over a distance of 2 m can be calculated as
Sangle = tan-1((1 m) / (2 m))
= 26.6°
Slope expressed as Grade
Sgrade(%) = (100 %) y / x (2)
where
Sgrade(%) = grade (%)
Example - Slope as Grade
Slope as grade for an elevation of 1 m over a distance of 2 m can be calculated as
Sgrade(%) = (1 m) / (2 m)
= 50 %
Slope and Roof Pitch
Roof pitch is the slope created by the rafter. You can find the roof pitch in the form of x:12 like 4/12 or 9/12.
Roof pitch on the form x:12 can be expressed in grades as
Sgrade(%) = (100 %) x / 12 (3)
Example - Roof Picth 4/12 as Grade
Sgrade(%) = (100 %) 4 / 12
= 33.3 %
Roof pitch on the form x:12 can be expressed in angles as
Sangle = tan-1(x / 12) (3b)
Example - Roof Picth 4/12 as Angle
Sangle = tan-1(4 / 12)
= 18.4°
Inclination or Slope Calculator
Calculate angle degrees, grade and length of slope.
(enable pop-up)
Inclination or Slope Chart
Use this chart to estimate the inclination or slope. Measure the horizontal run and the vertical rise and draw the lines in the chart to estimate inclination.
Download and print Inclination/Slope Chart
Slopes vs. gradients vs. % grades
| Angle (degrees) | Gradient | Grade (%) | |
|---|---|---|---|
| Y | X | ||
| 0.1 | 1 | 573.0 | 0.17 |
| 0.2 | 1 | 286.5 | 0.35 |
| 0.3 | 1 | 191.0 | 0.52 |
| 0.4 | 1 | 143.2 | 0.70 |
| 0.5 | 1 | 114.6 | 0.87 |
| 0.57 | 1 | 100 | 1 |
| 0.6 | 1 | 95.49 | 1.05 |
| 0.7 | 1 | 81.85 | 1.22 |
| 0.8 | 1 | 71.62 | 1.40 |
| 0.9 | 1 | 63.66 | 1.57 |
| 1 | 1 | 57.29 | 1.75 |
| 2 | 1 | 28.64 | 3.49 |
| 3 | 1 | 19.08 | 5.24 |
| 4 | 1 | 14.30 | 6.99 |
| 5 | 1 | 11.43 | 8.75 |
| 5.71 | 1 | 10 | 10 |
| 6 | 1 | 9.514 | 10.5 |
| 7 | 1 | 8.144 | 12.3 |
| 8 | 1 | 7.115 | 14.1 |
| 9 | 1 | 6.314 | 15.8 |
| 10 | 1 | 5.671 | 17.6 |
| 11 | 1 | 5.145 | 19.4 |
| 12 | 1 | 4.705 | 21.3 |
| 13 | 1 | 4.331 | 23.1 |
| 14 | 1 | 4.011 | 24.9 |
| 15 | 1 | 3.732 | 26.8 |
| 16 | 1 | 3.487 | 28.7 |
| 17 | 1 | 3.271 | 30.6 |
| 18 | 1 | 3.078 | 32.5 |
| 19 | 1 | 2.904 | 34.4 |
| 20 | 1 | 2.747 | 36.4 |
| 21 | 1 | 2.605 | 38.4 |
| 22 | 1 | 2.475 | 40.4 |
| 23 | 1 | 2.356 | 42.4 |
| 24 | 1 | 2.246 | 44.5 |
| 25 | 1 | 2.145 | 46.6 |
| 26 | 1 | 2.050 | 48.8 |
| 27 | 1 | 1.963 | 51.0 |
| 28 | 1 | 1.881 | 53.2 |
| 29 | 1 | 1.804 | 55.4 |
| 30 | 1 | 1.732 | 57.7 |
| 31 | 1 | 1.664 | 60.1 |
| 32 | 1 | 1.600 | 62.5 |
| 33 | 1 | 1.540 | 64.9 |
| 34 | 1 | 1.483 | 67.5 |
| 35 | 1 | 1.428 | 70.0 |
| 36 | 1 | 1.376 | 72.7 |
| 37 | 1 | 1.327 | 75.4 |
| 38 | 1 | 1.280 | 78.1 |
| 39 | 1 | 1.235 | 81.0 |
| 40 | 1 | 1.192 | 83.9 |
| 41 | 1 | 1.150 | 86.9 |
| 42 | 1 | 1.111 | 90.0 |
| 43 | 1 | 1.072 | 93.3 |
| 44 | 1 | 1.036 | 96.6 |
| 45 | 1 | 1.000 | 100.0 |
| 46 | 1 | 0.9657 | 103.6 |
| 47 | 1 | 0.9325 | 107.2 |
| 48 | 1 | 0.9004 | 111.1 |
| 49 | 1 | 0.8693 | 115.0 |
| 50 | 1 | 0.8391 | 119.2 |
| 51 | 1 | 0.8098 | 123.5 |
| 52 | 1 | 0.7813 | 128.0 |
| 53 | 1 | 0.7536 | 132.7 |
| 54 | 1 | 0.7265 | 137.6 |
| 55 | 1 | 0.7002 | 142.8 |
| 56 | 1 | 0.6745 | 148.3 |
| 57 | 1 | 0.6494 | 154.0 |
| 58 | 1 | 0.6249 | 160.0 |
| 59 | 1 | 0.6009 | 166.4 |
| 60 | 1 | 0.5774 | 173.2 |
| 61 | 1 | 0.5543 | 180.4 |
| 62 | 1 | 0.5317 | 188.1 |
| 63 | 1 | 0.5095 | 196.3 |
| 64 | 1 | 0.4877 | 205.0 |
| 65 | 1 | 0.4663 | 214.5 |
| 66 | 1 | 0.4452 | 224.6 |
| 67 | 1 | 0.4245 | 235.6 |
| 68 | 1 | 0.4040 | 247.5 |
| 69 | 1 | 0.3839 | 260.5 |
| 70 | 1 | 0.3640 | 274.7 |
| 71 | 1 | 0.3443 | 290.4 |
| 72 | 1 | 0.3249 | 307.8 |
| 73 | 1 | 0.3057 | 327.1 |
| 74 | 1 | 0.2867 | 348.7 |
| 75 | 1 | 0.2679 | 373.2 |
| 76 | 1 | 0.2493 | 401.1 |
| 77 | 1 | 0.2309 | 433.1 |
| 78 | 1 | 0.2126 | 470.5 |
| 79 | 1 | 0.1944 | 514.5 |
| 80 | 1 | 0.1763 | 567.1 |
| 81 | 1 | 0.1584 | 631.4 |
| 82 | 1 | 0.1405 | 711.5 |
| 83 | 1 | 0.1228 | 814.4 |
| 84 | 1 | 0.1051 | 951.4 |
| 85 | 1 | 0.08749 | 1143 |
| 86 | 1 | 0.06993 | 1430 |
| 87 | 1 | 0.05241 | 1908 |
| 88 | 1 | 0.03492 | 2864 |
| 89 | 1 | 0.01746 | 5729 |
| 90 | 1 | 0.00000 | ∞ |
- 1% grade = 0.57 degrees = 1 cm per 100 cm = 1 inch per 100 inches = 0.125 inch per foot
Visual Tool Slope Diagram
Print this diagram and hold it up against an object to estimate the slope.
Download Visual Tool Slope Diagram as pdf file
Vertical Rise, Horizontal Run and Slope Length
