Elevation Grade Calculator
Find the grade (slope) between two points as a percentage, fraction and angle, or the rise or run for a given grade.
Change the values and press Calculate to work out your own figures.
Grade from rise and run
Enter the rise and the run.
Show the working
- grade = rise ÷ run; percent = grade × 100; angle = atan(grade)
Rise from grade and run
Enter the run and the grade.
Show the working
- rise = run × grade
Run from grade and rise
Enter the rise and the grade.
Show the working
- run = rise ÷ grade
How to use it
Enter the rise and the run. Enter the run and the grade. Enter the rise and the grade.
Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.
Key facts
grade = rise ÷ run; percent = grade × 100; angle = atan(grade)
Common grades
Drainage away from a house: at least 2% (1/4 in per foot). Wheelchair ramps: at most 8.33% (1:12).
Questions
What grade is a 25 ft rise over 80 ft?
31.25% (17.35°).
How long must a ramp be to rise 2 ft at 1:12?
24 ft (8.33%).
Formulas
grade = rise ÷ run; percent = grade × 100; angle = atan(grade)
Sources
Limitations
- Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
- Tank results are the geometric volume; real tanks have wall thickness and fittings.