**Use this wheelchair ramp slope calculator to measure the appropriate length and angle of a ramp for safe and comfortable handicap ramp access. **

A building entrance with a

30-inch height differencefrom ground level. Ahandicap ramp slope / length calculatormight suggest a ramp length of30 feetto achieve a1:12 slope ratio, which is generally considered thegold standardfor wheelchair accessibility.

## Wheelchair Ramp Slope Calculator

Rise (inches) | Slope Ratio | Ramp Length (inches) | Ramp Length (feet) |
---|---|---|---|

12 | 1:12 | 12 | 1 |

12 | 1:10 | 10 | 0.83 |

12 | 1:8 | 9 | 0.75 |

24 | 1:12 | 24 | 2 |

24 | 1:10 | 20 | 1.67 |

24 | 1:8 | 18 | 1.5 |

36 | 1:12 | 36 | 3 |

36 | 1:10 | 30 | 2.5 |

36 | 1:8 | 27 | 2.25 |

48 | 1:12 | 48 | 4 |

48 | 1:10 | 40 | 3.33 |

48 | 1:8 | 36 | 3 |

60 | 1:12 | 60 | 5 |

60 | 1:10 | 50 | 4.17 |

60 | 1:8 | 45 | 3.75 |

72 | 1:12 | 72 | 6 |

72 | 1:10 | 60 | 5 |

72 | 1:8 | 54 | 4.5 |

84 | 1:12 | 84 | 7 |

84 | 1:10 | 70 | 5.83 |

84 | 1:8 | 63 | 5.25 |

96 | 1:12 | 96 | 8 |

96 | 1:10 | 80 | 6.67 |

96 | 1:8 | 72 | 6 |

## Wheelchair Ramp Slope Formula

The formula for calculating **wheelchair ramp slope** is:

**Slope Ratio = Rise : Run**

Where:

**Rise**is the vertical height difference**Run**is the horizontal length of the ramp

This ratio is typically expressed as **1:X**, where X represents the horizontal distance required for every 1 unit of vertical rise. For instance, a slope of **1:12** means that for every 1 inch of rise, the ramp extends **12 inches horizontally**.

**To calculate the required ramp length, use this formula:**

**Ramp Length = Rise × Slope Ratio**

For example, if you have a **24-inch rise** and want a **1:12 slope**: Ramp Length = 24 inches × 12 = **288 inches (24 feet)**

## How Long Should a Ramp Be for 24 Inches?

Using the **ADA-recommended 1:12 slope**:

**1:10 slope:**24 inches × 10 =**240 inches (20 feet)****1:8 slope:**24 inches × 8 =**192 inches (16 feet)**

For a **24-inch rise**, the ideal ramp length depends on the desired slope ratio.

**Ramp Length = 24 inches × 12 = 288 inches (24 feet)**

## How Long Should a Ramp Be for a 3-Foot Rise?

Using the preferred **1:12 slope**:

**1:10 slope:**36 inches × 10 =**360 inches (30 feet)****1:8 slope:**36 inches × 8 =**288 inches (24 feet)**

A **3-foot (36-inch) rise** requires careful consideration to ensure accessibility.

**Ramp Length = 36 inches × 12 = 432 inches (36 feet)**

## What is the Proper Slope for a Wheelchair Ramp?

The widely accepted standard is a **1:12 slope ratio**.

This **1:12 ratio** strikes a balance between accessibility and practicality:

- It’s gentle enough for most wheelchair users to navigate independently
- It minimizes the risk of tipping or losing control
- It complies with ADA (
**Americans with Disabilities Act**) guidelines for public buildings

In some cases, slightly steeper slopes may be permissible:

**1:10 for short ramps**(up to 6 inches of rise)**1:8 for very short ramps**(up to 3 inches of rise) in residential settings

## How Long Should a Ramp Be for 4 Steps?

Assuming standard step heights of **7 inches**:

**1:10 slope:**28 inches × 10 =**280 inches (23.33 feet)****1:8 slope:**28 inches × 8 =**224 inches (18.67 feet)**

To determine the appropriate ramp length for **4 steps**, we first need to calculate the total rise.

**Total Rise = 4 steps × 7 inches = 28 inches**

Now, applying the recommended **1:12 slope ratio**:

Ramp Length = 28 inches × 12 = **336 inches (28 feet)**

## References

- ADA.gov – 2010 ADA Standards for Accessible Design: https://www.ada.gov/2010ADAstandards_index.htm
- U.S. Access Board – Ramps and Curb Ramps: https://www.access-board.gov/ada/guides/chapter-4-ramps-and-curb-ramps/
- National Council on Independent Living – Ramp Projects: https://ncil.org/ramp-projects/

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