What's the slope of this surface?
Lay your phone flat on the surface to read the grade — or type a rise and run by hand. Works for driveways, drains, ramps, and grading.
Enter rise and run
Result
Start the phone meter or enter a rise and run
How is this calculated?
Slope can be written four ways for the same grade: degrees (the angle), percent (rise ÷ run × 100), inches per foot (rise in inches over 1 ft of run), and a ratio 1 : N (1 unit of rise per N of run).
Common targets:
- Slab / paving drainage — minimum: 1% (≈ 1/8 in per ft)
- Slab / paving drainage — comfortable: 2% (≈ 1/4 in per ft)
- ADA ramp — maximum: 8.33% (1 : 12)