Ramp Calculator

Building a ramp, especially for wheelchair accessibility, requires careful planning to ensure it is both safe and functional. The most critical factor in ramp design is its slope. Our Ramp Calculator helps you determine the required ramp length to achieve a specific slope, adhering to standards like those set by the Americans with Disabilities Act (ADA).

Understanding Ramp Slope and ADA Guidelines

Ramp slope determines how steep the ramp is. It's expressed as a ratio of the vertical "rise" to the horizontal "run".

• Rise: The total vertical height the ramp needs to overcome (e.g., the height of the steps).
• Run: The total horizontal length of the ramp.
• Slope Ratio: Expressed as 1:Run. For example, a 1:12 slope means for every 1 inch of vertical rise, the ramp must have 12 inches of horizontal run.

The ADA has specific guidelines for accessibility ramps to ensure they are safe for wheelchair users:

• Recommended Slope: The ADA recommends a slope of 1:12 for commercial and public spaces. This means for every inch of rise, you need one foot of ramp run.
• Maximum Slope for existing structures: In some situations where space is limited, a steeper slope of 1:10 or even 1:8 may be permissible, but 1:12 is the standard for safety and ease of use.
• Landings: For every 30 feet of ramp run, a flat landing of at least 5x5 feet is required. Landings are also required at the top and bottom of the ramp and wherever the ramp changes direction.

Why Is Slope So Important?

A ramp that is too steep can be dangerous. For a wheelchair user, it can be difficult or impossible to ascend without assistance and extremely hazardous to descend, risking a runaway situation. For someone walking with a cane or walker, a steep ramp increases the risk of falls. Adhering to established slope guidelines like the ADA's 1:12 ratio is crucial for safety and usability.

Frequently Asked Questions (FAQ)

What is the best slope for a residential ramp?

While private residences are not required to follow ADA guidelines, the 1:12 slope is still the recommended standard for safety and comfort. If space is extremely limited, a 1:10 slope might be used, but anything steeper should be avoided if possible.

Does the calculator account for landings?

The calculator determines the length of a single ramp section. According to ADA guidelines, a single ramp run should not be longer than 30 feet. If your calculated run exceeds 30 feet, you must break it up into multiple sections with flat landings in between.

What material should I use for a ramp?

Ramps can be built from wood, concrete, or modular aluminum systems. The best choice depends on budget, permanence, and climate. All surfaces should be non-slip, even when wet.