What Is an Inch per Foot Slope?
An inch-per-foot slope describes vertical change over a horizontal distance. For example, a slope of 0.5 inch per foot means the surface rises or falls by 0.5 inches for every 1 foot of horizontal run.
This measurement is commonly used for drainage layouts, pipes, gutters, driveways, walkways, landscaping, and construction projects.
How to Use the Inch per Foot Slope Calculator
- Measure the total vertical rise or fall in inches.
- Measure the horizontal run in feet.
- Enter both measurements into the calculator.
- The calculator returns the slope in inches per foot.
Use the horizontal distance, not the diagonal length of the sloped surface.
Inch per Foot Slope Formula
Slope in Inches per Foot=Run in FeetRise in Inches
Example Calculation
Suppose a surface has:
- Vertical rise: 6 in
- Horizontal run: 12 ft
Slope in Inches per Foot=126=0.5
The slope is 0.5 inches per foot.
This means the surface changes height by 0.5 inches for every foot of horizontal distance.
Why Calculate Slope in Inches per Foot?
Calculating slope helps you:
- Plan surface drainage
- Design gutters and drainage channels
- Lay out driveways and walkways
- Check landscaping grades
- Measure pipe fall
- Estimate elevation changes across a project area
Frequently Asked Questions
What does 1 inch per foot mean?
A 1 inch per foot slope means the surface rises or falls by 1 inch for every 1 foot of horizontal distance.
Can I use this calculator for drainage?
Yes. It can help calculate the slope of drains, gutters, swales, channels, and similar drainage features.
Should I measure the diagonal slope length?
No. Use the horizontal run, which is the flat distance between the start and end points.
Can I calculate a downward slope?
Yes. Use the vertical drop as the rise measurement. The result tells you how much the surface falls per foot.
Can I use inches and feet together?
Yes. This calculator is specifically designed for rise in inches and run in feet.
Does this calculator check building-code compliance?
No. It calculates the slope mathematically. Required slopes for ramps, drains, driveways, and other installations depend on local rules and project specifications.
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