Shed ramp planning

Shed Ramp Calculator

Calculate shed ramp length, slope, and angle for a shed, garage, mower shed, or small outbuilding. Enter the rise from ground to floor, choose a slope ratio such as 6:1, 8:1, or 12:1, then estimate ramp run, surface length, plywood sheets, traction cleats, and project cost.

Recommended ramp run 8 ft 12 in rise at an 8:1 slope, about 7.1°.
Ramp size

Example: an 8:1 slope means 8 inches of horizontal run for every 1 inch of rise. Use a gentler ratio when space allows.

Material estimate

Sheet and cleat counts are planning estimates. Actual framing, joists, hinges, anchors, and surface material depend on your design and load.

Quick answer: shed ramp calculator

To calculate a shed ramp, multiply the shed floor rise by your slope ratio for the horizontal run. For example, a 12 inch rise at an 8:1 slope needs 96 inches, or 8 feet, of run. The calculator also shows the ramp surface length, angle, grade, sheet count, cleat count, and estimated material cost.

How to use the shed ramp calculator

  1. Measure the rise from the ground or landing surface to the finished shed floor.
  2. Choose a slope ratio. Larger ratios create longer, gentler ramps.
  3. Enter the ramp width you want for your mower, cart, bins, or doorway.
  4. Adjust sheet cost, cleat spacing, and waste allowance for a quick buying estimate.

For lawn mowers and carts, a ramp that is a little longer than the bare minimum is often easier to use. Leave room for the door swing, add a firm landing at the bottom, and use a textured surface for traction in wet weather.

Shed ramp length examples

If your shed floor is 12 inches above the ground, a 6:1 ramp needs about 6 feet of horizontal run, an 8:1 ramp needs about 8 feet, and a 12:1 ramp needs about 12 feet. A riding mower, wheelbarrow, or loaded cart usually feels better on the longer option if your yard has room.

For an 18 inch rise, the same ratios become about 9 feet, 12 feet, and 18 feet of run. Use the calculator above to check your exact rise, width, surface length, and material estimate before buying lumber.

Common shed ramp lengths by rise

For a quick planning check, multiply the rise by the slope ratio. A 10 inch rise at 8:1 needs about 80 inches of run. A 14 inch rise at 8:1 needs about 112 inches, or 9 ft 4 in. A 16 inch rise at 10:1 needs about 160 inches, or 13 ft 4 in.

If the calculated shed ramp length feels too long for the available space, compare a compact 6:1 option with a gentler 8:1 or 10:1 option before cutting lumber. Steeper ramps save space, but they can be harder for riding mowers, carts, and wet shoes.

Shed ramp slope ratio guide

Use 6:1 when space is tight and the ramp only needs light use. Use 8:1 for many mower shed ramps and garden carts. Use 10:1 or 12:1 when you want a gentler slope, heavier equipment feels hard to push, or wet traction is a concern.

Before building, test whether the mower deck, cart wheels, or snow blower will clear the threshold. A slightly longer ramp with a flat landing is usually easier and safer than the shortest ramp that fits.

Shed ramp calculator FAQ

What does an 8:1 shed ramp slope mean?

An 8:1 slope means the ramp runs 8 inches horizontally for every 1 inch of vertical rise. A 12 inch rise at 8:1 needs 96 inches, or 8 feet, of horizontal run.

How wide should a shed ramp be?

Many shed ramps are 36 to 60 inches wide. Measure your doorway and the widest item you plan to move, then leave comfortable side clearance.

How long should a shed ramp be for a 12 inch rise?

For a 12 inch rise, an 8:1 shed ramp needs about 8 feet of horizontal run. A compact 6:1 ramp needs about 6 feet, while a gentler 12:1 ramp needs about 12 feet plus any landing space.

Can this calculator be used for wheelchair ramps?

It can show the math for a 12:1 or gentler slope, but accessibility ramps have specific landing, handrail, edge protection, width, and surface requirements. Check the rules that apply to your location and project.

What is the best shed ramp slope ratio for a mower?

An 8:1 to 12:1 slope is a common planning range for mower shed ramps when space allows. Shorter 6:1 ramps can work, but they are steeper and need good traction plus enough deck clearance.