Calculadora de Rampa (NBR 9050)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
comprimento = desnível / inclinação; máx 8,33% (NBR 9050)
About this calculator
The Ramp Calculator follows NBR 9050, the Brazilian standard for accessibility in buildings. It calculates the minimum length required for a ramp based on the height difference to be overcome and the maximum allowed slope. For residential use, the recommended maximum slope is 8.33% (1:12), ensuring safety and comfort for people with reduced mobility. The formula used is simple: length = height difference / slope. For example, for a 30 cm height difference with an 8.33% slope, the minimum length is 3.6 meters.
This tool is essential for architects, engineers, and homeowners planning to build or renovate a residence. It helps ensure the ramp meets accessibility standards, avoiding fines and rework. The calculator also allows adjusting the slope as needed, as long as it respects the maximum limit. Remember that smaller slopes increase length but are safer, especially for wheelchair users or people with mobility difficulties.
When using the calculator, enter the height difference in centimeters and the desired slope as a percentage. The result will be the ramp length in meters. Consider the available space on the site and the need for intermediate landings for very long ramps. For height differences over 1.5 m, NBR 9050 requires intermediate landings. The calculator does not replace the complete project but serves as a basis for initial sizing.
Frequently asked questions
What is the maximum slope for residential ramps according to NBR 9050?
For residential ramps, the recommended maximum slope is 8.33% (1:12). In exceptional cases, it can reach 10% for very small height differences, but always prioritizing accessibility.
Do I need intermediate landings on the ramp?
Yes, for height differences over 1.5 m or lengths exceeding 6 m, NBR 9050 requires intermediate landings with a minimum depth of 1.20 m to ensure safety.
Can I use a slope smaller than 8.33%?
Yes, smaller slopes are safer and more comfortable, but they increase the ramp length. Ideally, use the smallest possible slope within the available space.
How to measure the height difference correctly?
Measure the vertical difference between the highest and lowest points of the path, from floor to floor. Use a tape measure or laser level for accuracy. Small height differences, such as steps, also count.
Does the calculator consider the ramp width?
No, the calculator focuses only on length and slope. The minimum width for residential ramps is 90 cm, but 1.20 m is recommended to allow wheelchair maneuvers.