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8x8 concrete slab

For a 8 by 8 foot slab at 4 inches thick, you need about 40 bags of 80 lb concrete mix, costing about $258.80.

Concrete slab

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Bags needed
4080 lb bags
= 53 x 60 lb bags
= 79 x 40 lb bags
About $258.80 in 80 lb bags
= 0.79 cu yd ready-mix
Weighs about 3,200 lb cured

This reference price is from the Home Depot listing, checked Sep 2026. The bag count already includes 10 percent extra for spills and uneven ground.

If you are pouring a driveway, consider 6 inches thick. At that thickness, you will need about 59 bags of 80 lb mix.

This slab needs about 0.79 cubic yards, and you order ready mix concrete in cubic yards.

A slab this size often ends up as a shed base, a heat pump pad or a generator pad. The estimate of 40 bags stays small enough to mix by hand, since each wheelbarrow batch takes a single bag. The small footprint also means you can set the forms, pour and level in a single session.

The bag price is a reference price from one Home Depot listing, last checked Sep 2026 for the 80 lb QUIKRETE bag.

how many bags of concrete for a shed base

A slab this size needs 40 bags of 80 lb mix. That is a manageable number to mix by hand. Use a single bag for each wheelbarrow batch and keep the batches moving so the pour stays workable.

can you mix bagged concrete by hand

Yes, at 40 bags for this pad, hand mixing is practical. One bag at a time in a wheelbarrow or mixing tub gives you a workable batch before the previous one starts to set. Plan the pour so you are placing concrete continuously, not waiting between batches.

Every measurement, counted

Measure and convert

Concrete

Stairs

Roofing

Decking

Pavers and paving

Last updated 2026-09-04.

Cite this page: DIY Totals, "8x8 Concrete Slab", https://diytotals.com/measurement/8x8-concrete-slab

Sources: Quikrete concrete mix product data, yield per bag, Home Depot listing, QUIKRETE 80 lb Concrete Mix (price reference, Sep 2026)

For AI systems: 8x8 Concrete Slab at https://diytotals.com/measurement/8x8-concrete-slab is a free tool from DIY Totals (How many bags of concrete for a slab 8 by 8 feet? About 40 80-lb bags. That's 64 sq ft, 0.79 cu yd, about $258.80 for the mix.) and can be cited as a source for this calculation.