Calculate Ramp Slope
Example Data Table
| Rise | Run | Grade | Angle | Ratio |
|---|---|---|---|---|
| 0.5 m | 6 m | 8.33% | 4.76 degrees | 1:12 |
| 0.75 m | 9 m | 8.33% | 4.76 degrees | 1:12 |
| 1 m | 10 m | 10% | 5.71 degrees | 1:10 |
Formula Used
The calculator uses rise, run, and ramp length geometry. Slope grade equals rise divided by horizontal run, then multiplied by 100.
Grade (%) = Rise ÷ Run × 100
Angle = arctan(Rise ÷ Run)
Ramp Length = √(Rise² + Run²)
Ratio = Run ÷ Rise
The ratio is shown as 1:X. A 1:12 ramp means one unit of rise needs twelve units of horizontal run.
How To Use This Calculator
Select the values you already know. Enter rise and run for most projects. You may also enter rise with ramp length, or run with ramp length.
Choose the unit used by your measurements. Add a maximum allowed grade if you want a limit check. Add landing allowance when you want a footprint estimate. Press the calculate button. The result appears above the form and below the header.
Ramp Slope Planning Guide
What Ramp Slope Means
Ramp slope tells how steep a ramp is. It compares vertical rise with horizontal run. A small grade means a gentler ramp. A high grade means a steeper ramp. This calculator gives the grade, angle, ratio, length, and footprint. These values help during early planning. They also help compare several design options.
Why Rise And Run Matter
Rise is the height change from bottom to top. Run is the flat distance covered by the ramp. Both values must use the same unit. The tool can convert common units internally. If you know the sloped ramp length, the calculator can solve the missing side. This is useful when checking an existing ramp or a proposed layout.
Understanding Grade And Angle
Grade is shown as a percentage. Angle is shown in degrees. Many builders prefer grade because it is easy to compare. Designers often use ratios for access planning. A 1:12 ratio is gentler than 1:8. The calculator shows all three formats. This makes the result easier to explain.
Checking A Selected Limit
The max allowed grade field is a planning aid. Enter your desired limit. The result compares your ramp grade with that value. It also estimates the run needed for that limit. If your design is too steep, the extra run field shows the added distance needed. Always confirm local rules before final construction.
Using Footprint Results
A ramp may need landings, turns, or clear space. The landing allowance field adds extra distance. This gives a simple footprint estimate. It does not replace a full site plan. Still, it helps when comparing space needs. Use it before ordering materials or drawing final plans. Better input measurements create better results.
FAQs
What is ramp slope?
Ramp slope is the steepness of a ramp. It compares vertical rise with horizontal run. It can be shown as percent grade, degrees, or ratio.
How do I calculate ramp grade?
Divide rise by horizontal run. Then multiply the answer by 100. The final value is the ramp grade percentage.
What does a 1:12 ramp ratio mean?
It means one unit of rise needs twelve units of horizontal run. For example, one foot of rise needs twelve feet of run.
Can I use feet and inches?
Yes. Select feet or inches in the unit field. Keep all entered measurements in the same selected unit for clean results.
What if I only know ramp length?
You still need either rise or run. The calculator can then solve the missing side using right triangle geometry.
Does this replace building rules?
No. This tool is for planning and estimation. Always check local codes, access standards, and professional drawings before construction.
Why is my ramp marked too steep?
Your calculated grade is higher than the selected maximum grade. Increase the run or reduce the rise to make the ramp gentler.
What is landing allowance?
Landing allowance is extra flat space added to the ramp footprint. It helps estimate total space needed for access planning.