Slope Calculator
Looking for a quick and reliable way to calculate a slope, gradient, or angle? This free Universal Slope Calculator lets you instantly convert between degrees, percent, and fall. Whether you’re designing a roof pitch, setting the slope of a drain pipe, or checking the angle of a ramp, this tool provides precise results in both metric and imperial units — including fractional inches for U.S. builders. Simply enter any two values (length, drop, angle, or slope percentage) and the calculator will automatically compute the rest — including optional partial distance drops.
Construction Slope & Fall Calculator
Enter any two values to compute the rest — or use angle/percent with a partial distance.
How to Use the Slope Calculator
Using this slope calculator is simple.
Just enter any two known values — for example, total length and fall, or slope percentage and partial distance — and the tool instantly calculates the rest.You can switch between metric (mm, cm, m) and imperial (inch, ft) units, and results automatically adjust to the chosen system.For U.S. users, results are displayed in feet and fractional inches, while metric users get centimeters with commas for precision.
Example use cases:
- Designing a roof pitch or measuring rafter angles
- Calculating drainage fall or pipe slope
- Setting ramp inclines for accessibility
- Converting degrees to percent or percent to angle
Why Use This Universal Slope Calculator
This tool was built for professionals and DIY builders alike who need accurate slope calculations without complex math.
Unlike typical online tools, this calculator handles both metric and imperial systems, partial distance drops, and even fractional inches for precise field work.
Benefits include:
- Converts angle ↔ slope ↔ fall instantly
- Supports roof pitch, pipe fall, ramps, and gradients. And any other slope that you might need
- Works in cm, mm, m, inch, and feet
- Displays fractional inches (1/16”) automatically
- Responsive and mobile-friendly
- No downloads or registration required
Common Slope Calculations Explained
What is Slope (%)
Slope represents the ratio between vertical rise (or fall) and horizontal run.
For example, a 6% slope means the height changes by 6 units for every 100 units of length.
Formula:
\[
\\text{Slope (\\%)} = \\frac{\\text{Rise or Fall}}{\\text{Run}} \\times 100
\]
What is the Angle (°)
The angle is simply the slope expressed in degrees.
Use this calculator to convert slope % into degrees using the tan⁻¹ (arctangent) formula.
What is the Fall or Drop
Fall refers to the total vertical change between two points.
It’s often used in plumbing or roof design to ensure proper drainage or structural pitch.
Frequently Asked Questions (FAQ)
Q: Can I use this for roof pitch calculations?
Yes. Enter your total roof span and desired drop (or slope %), and the tool calculates the roof pitch angle automatically.
Q: Is this accurate for drainage and plumbing?
Absolutely. The calculator supports precise pipe fall values and converts between slope percentage and angle for plumbing layouts.
Q: Can I enter values in feet or inches?
Yes, imperial units are fully supported. The output automatically switches to fractional inches for realistic measurements.
Q: Can I calculate partial drops?
Yes — just enter your slope (or angle) and the partial distance. The tool shows exactly how much drop occurs over that segment.
Q: Do I need to install anything?
No — it’s fully browser-based and mobile-friendly. Just open, enter your values, and get instant results.