Shed ramp framing
Shed Ramp Stringer Calculator
Plan the framing under a shed ramp. Enter the rise, run, width, and spacing to estimate stringer length, ramp angle, stringer count, cross braces, decking boards, screws, and a rough lumber budget.
Quick answer: shed ramp stringers
For a 12 inch shed floor rise and 96 inch run, the ramp stringer length is about 97 inches, or 8 ft 1 in. A 48 inch wide mower ramp framed at 12 inches on center typically plans for 5 stringers: two outside stringers plus three middle stringers.
How to use the shed ramp stringer calculator
- Measure the vertical rise from the finished ground or landing to the shed floor.
- Enter the horizontal run from the shed face to the bottom of the ramp.
- Set the ramp width and the maximum stringer spacing you want to use.
- Adjust board prices to get a rough shopping-list estimate.
The calculator gives the diagonal stringer length, ramp angle, grade, stringer count, brace count, decking board count, and screw estimate. Always size framing for the actual equipment and load you plan to use.
Stringer spacing for shed ramps
Closer stringer spacing makes a shed ramp feel stiffer under mowers, carts, snow blowers, and heavy bins. A light garden ramp may use wider spacing with sturdy decking. A mower ramp often feels better with 12 to 16 inch spacing and strong bearing at the shed and ground ends.
If your ramp is wider than the doorway or will carry a riding mower, do not rely on the two outside boards only. Add intermediate stringers, blocking, and traction so the surface does not flex or get slippery.
Ramp angle and cut planning
The ramp angle is based on rise divided by run. A 12 inch rise with 96 inches of run is about 7.1 degrees. A 12 inch rise with 72 inches of run is about 9.5 degrees. Longer runs reduce the angle and make the ramp easier to roll up.
Use the angle as a layout guide, then test-fit your actual top connection and bottom landing. Threshold height, ledger boards, beveled bottoms, ground blocks, and door clearance can change the final cut details.
Shed ramp stringer calculator FAQ
How long should shed ramp stringers be?
The stringer length is the diagonal from the bottom of the ramp to the shed floor. For example, 12 inches of rise and 96 inches of run gives a stringer length of about 97 inches.
How many stringers do I need for a 4 foot wide shed ramp?
At 12 inch spacing, a 4 foot wide ramp usually plans for 5 stringers: one at each edge and three between them. At 16 inch spacing, it may plan for 4 stringers. Heavier ramps usually benefit from closer spacing.
Can I build a shed ramp with only two stringers?
Two outside stringers may be enough for a narrow, light-duty ramp with strong decking, but most wider shed ramps need intermediate stringers or blocking to reduce flex.
Does this calculator replace building plans?
No. It is a planning estimate for lengths and quantities. Check lumber span, fasteners, bearing, traction, drainage, and local requirements before building.