Slope Per Foot Calculator

Calculate slope percentage, angle, ratio, and inches per foot instantly. Perfect for construction, landscaping, drainage, and roofing projects.

Input Method

Unit System

Rise (Vertical) *

Run (Horizontal) *

Frequently used slopes in US construction & landscaping

Application	Slope %	Ratio	in/ft	Angle
Flat Roof (Min Drainage)	2%	1:50	1/4	1.15°
Shower Floor	2%	1:50	1/4	1.15°
Patio / Walkway Drainage	2%	1:50	1/4	1.15°
ADA Ramp (Max)	8.33%	1:12	1	4.76°
Driveway (Typical)	10%	1:10	1.2	5.71°
Drain Pipe (1/4" per ft)	2.08%	1:48	1/4	1.19°
Drain Pipe (1/8" per ft)	1.04%	1:96	1/8	0.60°
Standard Roof (4:12)	33.33%	1:3	4	18.43°
Steep Roof (8:12)	66.67%	2:3	8	33.69°
Highway Grade (Max)	6%	1:16.7	0.72	3.43°

Input the vertical rise and horizontal run. Select your preferred unit (inches, feet, yards, or metric). Results update instantly.

Switch input mode to enter a known angle in degrees or a slope percentage directly.

View slope percentage, angle, ratio, inches per foot, and slope length. Use the steepness gauge to quickly assess the grade.

Check the table for standard values used in US construction—ADA ramps, roof pitches, drainage grades, and more.

Results