Concrete Slope Calculator
Calculate concrete fall and drainage slope. Enter your run, choose a slope preset like 1/4"/ft, and see total fall in inches, feet, and centimeters plus percent grade and decimal slope.
Total fall10"
Total fall (in)10in
Total fall (ft)0.833ft
Total fall (cm)25.4cm
Percent grade2.083%
Decimal slope0.0208
Inches per foot0.25in/ft
Quick reference
1/8"/ft = 1.042%
1/4"/ft = 2.083%
3/8"/ft = 3.125%
1/2"/ft = 4.167%
1/4"/ft is a common drainage slope. Always verify project plans, engineering requirements, ADA rules and local code.
Frequently asked
- What slope is standard for a concrete patio?
- 1/4" per foot (about 2.083%) is the most common drainage slope for patios, sidewalks, and driveways.
- What is 1/4" per foot as a percent?
- 1/4"/ft ≈ 2.083% grade, or 0.0208 as a decimal slope.
- How much fall over 40 feet at 1/4"/ft?
- 10 inches of total fall (40 × 0.25).