Calculated result
4%
Slope
Formula
UTIL-GRD-001slope % = rise ÷ run × 100
25 :1
Ratio (run : 1)
2.29 °
Angle
2 ft
Rise
Utilities calculator
Slope calculator
2 ft of rise over 50 ft of run is 4%, a 1:25 slope and about 2.29°. In metric, rise is 0.61 m.
Formula. slope % = rise ÷ run × 100
Slope percent, ratio and angle from rise and run. Planning geometry only — not a drainage design.
By Feroz Sheikh · Formula UTIL-GRD-001 v1.0.0 · Tested formula
Formula
UTIL-GRD-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
Slope percent is rise ÷ run × 100. For a nonzero rise, the ratio is 1 in (run ÷ rise). At zero rise, no finite 1:n ratio exists, so the ratio line is omitted. Angle is arctangent of rise/run. Planning geometry only.
- Measure the horizontal run and the vertical rise between the same two points.
- A driveway, a drain and a ramp use the same math with different limits — this page does not pick the limit.
- Switch to the wheelchair-ramp calculator when you need run from a stated 1:12 ratio.
Add your project costs
Add rates if you are pricing a related project line. Pick a currency — badges, inputs, and totals follow.
This page is geometry, not a material takeoff. Leave rates at zero unless you are pricing a related line. Construclytic does not fetch supplier prices.
How this calculator works
A transparent grade and slope takeoff.
Feroz SheikhWritten and reviewed by Feroz Sheikh · founder
Slope percent is rise ÷ run × 100. For a nonzero rise, the ratio is 1 in (run ÷ rise). At zero rise, no finite 1:n ratio exists, so the ratio line is omitted. Angle is arctangent of rise/run. Planning geometry only.
UTIL-GRD-001 turns rise and run into slope percent, ratio and angle. It is planning geometry, not a drainage design and not a road spec. Formula ID stays on the sheet.
Worked example. Example: 2 ft of rise over 50 ft of run is 4%, a 1:25 slope and about 2.29°.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Run | 50 ft |
| Rise | 2 ft |
Example result: Slope — 4 %.
slope % = rise ÷ run × 100
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure the horizontal run and the vertical rise between the same two points.
- 2. A driveway, a drain and a ramp use the same math with different limits — this page does not pick the limit.
- 3. Switch to the wheelchair-ramp calculator when you need run from a stated 1:12 ratio.
Field notes that change the number
- Use the same units for rise and run.
- A 2% site slope is not a 6:12 roof pitch — different tools.
- Accessibility ramps have their own calculator.
Common mistakes
- Entering an angle in degrees as if it were percent.
- Using roof pitch here.
- Calling this a drainage or ADA stamp.
Need the broader workflow? Read the utilities planning guide.
How-to: Slope percent, ratio and degrees: convert the same rise and run
Questions
Questions about grade and slope
Percent vs ratio?
4% is the same slope as 1:25. Percent is 100 × rise/run. Ratio is run per 1 of rise.
What happens at zero rise?
Slope and angle are both zero. A finite 1:n ratio would require division by zero, so the calculator omits that ratio instead of displaying a false value.
Is this a drainage design?
No. Pipe size, inlet spacing and soil are not in this triangle.
What is the formula ID?
This slope calculator publishes formula UTIL-GRD-001, version 1.0.0. The ID stays on the result and on the estimate line.