Shed Foundation Skid Calculator

SettingsSettings for this calculationUS

Market

Imperial · sales tax

Shed Width

The width of the shed, across which skids are spaced.

Measure the shed's floor width.

Shed Length

The length of the shed, which sets each skid's length.

Each skid runs the full length of the shed floor.

Skids needed

6 skids

Medium confidence

This assumes a standard 2 ft (0.61 m) skid spacing suitable for typical small-to-mid-size sheds — larger sheds or heavier floor loads may need closer spacing or a different foundation type (concrete piers or a full slab) per your local code.

Length of each skid: 12 ft

Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

Skid count = (shed width / skid spacing) + 1; each skid runs the full length of the shed, spaced at a standard 2 ft interval across the width

Inputs used

Shed Width: 10 ft
Shed Length: 12 ft

Intermediate steps

Length of each skid: 12 ft

Final result6 skids

Confidence note: This assumes a standard 2 ft (0.61 m) skid spacing suitable for typical small-to-mid-size sheds — larger sheds or heavier floor loads may need closer spacing or a different foundation type (concrete piers or a full slab) per your local code.

What this calculation does not cover

The count comes from the Shed Width field alone — width decides how many runners, while length only sets how long each one is — so typing the two dimensions the other way round returns a different number of skids, and the layout takes it for granted that the floor joists cross the runners rather than sitting parallel to them.
Skid size is never chosen here: there is no entry for a 4x4 against a 4x6, or for species and grade, so the beam depth carrying the floor between its bearing points, and the joist span across the gap between runners, still have to be sized on their own.
Ground preparation sits outside the answer entirely — the gravel bed beneath the runners, its depth and footprint, the levelling work, and any blocks or pads the skids rest on are none of them counted, and the result behaves as though the ground is already flat and draining.
Each skid is reported at exactly the shed's length, with no overhang past the floor frame for skidding or blocking, no cutting allowance, and no rounding to a stock beam length, so a runner that lands between sizes is still bought at the next length up and a shed longer than the longest beam available needs a splice this figure does not reveal.
Nothing in the result holds the building down: the fasteners between the floor frame and the runners, and any tie-down against wind uplift or sliding, are separate from how many skids lie underneath, and a shed on skids rests on the ground rather than being fixed into it.

Estimated cost — your price

Price per skid ($)

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-05 · in the site-wide review of 2026-09-06 · v1.0.1

Regulatory standards & verification citations1

Skid count = (shed width / skid spacing) + 1; each skid runs the full length of the shed, spaced at a standard 2 ft interval across the width

Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Now that you have the number

These guides cover the work this quantity is for — the first ones run this calculator inside the section that raises the question.

Choosing and Building a Base for a Garden Roomuses this calculator

Slab, pads, ground screws or steel — chosen by the fall across the plot, the clay under it, the trees around it and the width of the side gate.

Founding and Anchoring a Shed or Pergolauses this calculator

A flat-pack kit settles everything except the runner grid under it, the post positions it has to land on, and the hold-down it ships without.

Frequently asked questions

What are skids and why do small sheds use them?

Skids are pressure-treated wood beams (often 4x4 or 4x6) that the shed floor framing rests on, raising it off the ground — they're a simpler, cheaper alternative to a concrete foundation for smaller, lighter sheds, and allow the structure to be skidded or moved.

Do skids need to sit on anything, or just the ground?

Most installations set skids on a bed of compacted gravel for drainage and stability, rather than directly on bare soil, which helps prevent rot and uneven settling over time.

When should I use a different foundation type instead?

Larger or heavier sheds, sheds in areas with expansive or poorly-draining soil, or sheds requiring a permit often need a more substantial foundation (concrete piers or a slab) rather than a simple skid foundation — check your local code and shed size.