Elevation Difference Calculator
Subtract two hub, invert, or finish-grade elevations. The result is the signed difference (positive means the second point is higher) plus the absolute cut/fill in feet and inches.
Enter your values, then press Calculate.
How to calculate
Enter elevation A (start, existing, or invert) and elevation B (end, finish, or hub). Use the same datum for both. The calculator reports how much B is above A, and the absolute difference for cut/fill.
Formula
Difference (ft) = elevation B − elevation A. Absolute difference is |B − A|. Inches = absolute difference × 12.
Common use cases
- Hub-to-hub shots
- Invert to finish-grade checks
- Cut/fill between two plan elevations
- Converting a decimal-foot shot to inches
Worked example
Example: 102.50 minus 100.00 is 2.50 ft
1. B minus A
102.5 − 100 = 2.5 ft
2. Absolute difference in inches
2.5 ft × 12 = 30 in
Related calculators
- Percent Grade CalculatorConvert rise and run into percent grade, slope ratio, and feet per 100 feet.
- Station Difference CalculatorFind the distance between two stations in the 100-foot stationing system.
- Pipe Slope CalculatorConvert elevation drop and run into percent grade, ratio, and inches per foot.
FAQ
Why is the difference negative?
Negative means elevation B is below A. Use the absolute difference when you only need cut or fill magnitude.
Can I mix feet and inches?
Yes. Each elevation has its own unit. Both are converted to feet before subtracting.
Disclaimer
These calculators are estimating tools for planning and field checks. They are not a substitute for approved plans, specifications, licensed professional engineering, or governing standards. Confirm densities, waste factors, and yields with your supplier and project documents.