Ramp Slope Calculator

A 600 mm rise at a gradient of 1 in 12 needs 7200 mm of horizontal ramp.

Find:

Ramp length for a rise and gradientGradient from a rise and horizontal length

Vertical rise (mm):

Gradient 1 in:

Accessible ramps: 1:12 maximum (NBC 2016, ADA); 1:15–1:20 preferred.

Horizontal ramp length =

7200 mm

Precision

Slope: 8.333333333 %
Angle: 4.763641691 °
Sloping length: 7224.956747 mm
Accessibility: meets 1:12
Intermediate landings for 9 m (9000 mm) maximum runs: 0

Step-by-step solution

Length = rise × ratio
Slope = rise ÷ run = 600 ÷ 7200 = 8.333333333 %

Ramp Slope Formula

Length = rise × n (for a 1 in n gradient)

slope % = 100 × rise/run; accessible maximum 1:12 (8.33 %)

Worked Example

A 600 mm rise at 1 in 12:

Length = rise × ratio
Slope = rise ÷ run = 600 ÷ 7200 = 8.333333333 %

Angle: 4.763641691 ° · Sloping length: 7224.956747 mm · Accessibility: meets 1:12 · Intermediate landings for 9 m (9000 mm) maximum runs: 0

GATE tip

Gradient “1 in 12” is rise ÷ run, not rise ÷ sloping length; the difference is small but matters in NAT answers.

More Circulation and Construction Calculators

Staircase Design Calculator

Risers = ⌈H / R_max⌉, 2R + T ≈ 600–640 mm

treads = risers − 1 per flight

Example: A 3 m floor height with risers up to 175 mm and 250 mm treads in a dog-legged stair: Number of risers = 18.

Open the staircase design calculator →

Frequently asked questions

What gradient is accessible?

NBC 2016 and the ADA allow at most 1:12 for wheelchair ramps, with gentler slopes preferred.

How long can a ramp run without a landing?

About 9 m (30 ft) of run, or 750 mm of rise, before a level landing of at least 1.5 m.

Sources

The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.

Cite this page

APA

Scientific Converters. (2026, October 15). Ramp Slope Calculator. Retrieved October 29, 2026, from https://scientificconverters.com/calculators/ramp-slope-calculator/

IEEE

Scientific Converters, "Ramp Slope Calculator," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/calculators/ramp-slope-calculator/