How Many Bags of Concrete for a 10×10 Slab?
The 10×10 ft patio slab is the most common DIY concrete job searched every spring. At 4 inches thick it needs 33.3 cubic feet of concrete — about 56 eighty-pound bags before waste. This guide walks the exact math (volume to bags to dollars), shows when a ready-mix truck beats bags, and sets the curing schedule so the slab reaches full strength.
Step-by-Step Takeoff
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1
Prep the subgrade: excavate 7–8 in, compact 4 in of crushed gravel base, set forms level with a 1/8-in-per-foot fall for drainage.
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2
Measure 10 ft by 10 ft and confirm 4 in thickness (0.333 ft).
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3
Volume: 10 × 10 × 0.333 = 33.3 cu ft ÷ 27 = 1.23 cu yd.
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4
Bags: 33.3 ÷ 0.6 per 80 lb bag = 56 bags; add 5% waste = 59 bags.
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5
Cost check: 59 bags × your local bag price versus a 1.5-yard ready-mix short load (watch minimums and short-load fees).
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6
Place, screed, float, and edge in one session; start curing within 2 hours.
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7
Cure damp 7 days; foot traffic after 24–48 hours, heavy loads after 7 days. Run your exact numbers in the Concrete Calculator and export the quote.
Guide FAQ
Should I use bags or ready-mix for 1.23 yards?
Bags — ready-mix minimums and short-load fees make 1.23 yards expensive by truck. Above ~2 yards the truck wins.
How thick should a patio slab be?
4 inches for foot traffic; 5–6 inches if vehicles will cross it.
How many 60 lb bags for a 10x10 slab?
About 75 sixty-pound bags (0.45 cu ft each) plus waste — 80 lb bags are cheaper per yard when you can lift them.
How long before rain hits fresh concrete?
Light rain after final set (~4–6 hours) is fine; cover the slab if heavy rain threatens within 24 hours.
How much gravel base under a patio?
4 inches of compacted crushed stone — price it in the Gravel Calculator before you order.
Related Guides
How to Cure Concrete in Hot Weather?
Curing schedule, ponding depths, water needs, and strength targets for concrete above 35C.
How Much Gravel for a Driveway?
Cubic yards, tons, delivery cost, and base depth for a 20x40 ft driveway at 4 inches deep.
How Much Fence for a 100 ft Yard Run?
Posts, pickets, rails, gate hardware, and post-hole concrete for a 100-foot privacy run with one gate.