Cubic feet
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Project guide
Concrete for a Shed Base?
How much concrete for a shed floor or base — the right thickness for a shed, when a slab beats gravel, and the calculator to size it.
Dimensions
FIG. 01Volume ÷ 27 = cubic yards. Pros order to the nearest ½ yard and add a waste margin — running short mid-pour risks a cold joint.
You need
—cu yd
Order to nearest ½ yd → — · —
Cubic meters
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80 lb bags
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60 lb bags
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Est. weight
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Best buy
see above
Sizing it right
A shed slab is one of the most common DIY pours, and usually small enough that the bag-vs-truck decision actually matters.
4 inches is enough
Unlike a garage, a shed floor carries light loads — 4 inches is standard, over a few inches of compacted gravel. Going thicker rarely buys you anything for a garden shed.
This is where bags can win
A typical 8×10 or 10×12 shed slab is around 1–1.5 cubic yards. That's right at the crossover where bagged concrete and a small ready-mix load are close on price. Run your exact size through the bags-vs-ready-mix calculator — below about a yard, bags usually win; above it, call a truck.
Slab vs. gravel base
If the shed is a kit on skids, you may only need a gravel pad, not concrete. Pour a slab when you want a permanent, level, rot-proof floor you can anchor to.
FAQ
How thick should a shed slab be?
4 inches over a compacted gravel base is standard for a garden or storage shed. That handles normal shed loads; only go thicker for heavy equipment.
How much concrete for a 10x12 shed?
About 1.5 cubic yards at 4 inches — right around the bag-vs-truck breakeven. Enter your size above and check the bags-vs-ready-mix tool to see which is cheaper for you.