How Much Concrete for a 10×10 Slab? (Bags, Yards & Worked Example)
October 20, 2025
Written by Shakeel Alvi · Technically reviewed by Muhammad Qasim, PEC Reg. No. 63430 · Last reviewed: 2025-10-20
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How Much Concrete Does a 10×10 Slab Need?
A 10×10 concrete slab poured 4 inches thick takes about 33.3 cubic feet — 1.23 cubic yards of concrete. Order 1.35 yd³ once you add a 10% waste allowance, or buy roughly 56 × 80 lb bags (about 75 × 60 lb bags) if you're mixing from bags. Bump the slab to 6 inches and the volume jumps 50% to 1.85 yd³.
Quick start: Skip the math and price your exact pour with the Slab Concrete Calculator — enter 10 ft × 10 ft, your thickness, and waste %, and it returns yards, bags, and cost.
A "10×10" means 100 square feet of surface area. The only other number you need is thickness, because volume = area × thickness — everything below flows from that.
The Formula for a 10×10 Slab
Concrete volume in the U.S. is figured in cubic yards, and one cubic yard is 27 cubic feet. The clean formula is:
Cubic yards = (Length ft × Width ft × Thickness ft) ÷ 27
The trap is thickness: it's almost always in inches, so convert to feet first by dividing by 12. A 4-inch slab is 4 ÷ 12 = 0.333 ft.
Worked example — 10×10 at 4 inches:
- Thickness: 4 in ÷ 12 = 0.333 ft
- Volume: 10 × 10 × 0.333 = 33.3 ft³
- Cubic yards: 33.3 ÷ 27 = 1.23 yd³
- Add 10% waste: 1.23 × 1.10 = 1.35 yd³ to order
10×10 Slab Concrete by Thickness
Thickness is the single biggest driver of how much you'll pour. This table assumes the full 100 ft² area, with the order column rounded up after a 10% waste allowance.
| Thickness | Volume (ft³) | Volume (yd³) | Order w/ 10% waste |
|---|---|---|---|
| 4 in | 33.3 | 1.23 | 1.35 yd³ |
| 5 in | 41.7 | 1.54 | 1.70 yd³ |
| 6 in | 50.0 | 1.85 | 2.05 yd³ |
Four inches is standard for patios and walkways; go to 5–6 inches for driveways, garage floors, or anything carrying vehicle loads. For the reasoning behind slab thickness and reinforcement, see how to calculate concrete for a slab.
How Many Bags of Concrete for a 10×10 Slab?
Bagged mix is sold by yield — the volume of wet concrete one bag makes. An 80 lb bag yields about 0.60 ft³, a 60 lb bag about 0.45 ft³, and a 40 lb bag about 0.30 ft³. Divide the slab volume by the yield, then add waste.
| Bag size | Bags (net, 4 in) | Bags w/ 10% waste |
|---|---|---|
| 80 lb | 56 | 62 |
| 60 lb | 75 | 82 |
| 40 lb | 111 | 122 |
That's a lot of bags. As a rule of thumb, once you pass 30–40 bags (about ½ yard), ready-mix is cheaper and far less work — see ready-mix vs bagged concrete. For the bag-by-bag method on smaller slabs, see how many bags of concrete for a slab.
What Does a 10×10 Slab Cost?
At the typical 8 per square foot installed, a 100 ft² slab runs roughly 800 for a plain broom finish — material, labor, and basic prep included. Pouring it yourself with bags costs less in material but trades money for labor. Full breakdown in how much does a concrete slab cost.
Ordering Tips
- Always round up. Ready-mix is sold in ¼-yard increments and you can't pour what you don't have. Running short mid-pour causes a cold joint.
- Add 10% waste for spillage, an uneven subgrade, and slight over-excavation. On rough ground, use 15%.
- Measure the actual depth. Forms settle and grades dip — a "4-inch" slab often averages 4.5 inches once poured.
- Prep the base first. A compacted gravel base and vapor barrier keep your thickness (and volume) consistent.
Frequently Asked Questions
How many yards of concrete for a 10x10 slab at 4 inches?
A 10×10 slab at 4 inches thick needs 1.23 cubic yards of concrete (33.3 ft³). Order about 1.35 cubic yards to cover a 10% waste allowance, since ready-mix comes in quarter-yard increments and you can't be short during the pour.
How many bags of concrete do I need for a 10x10 slab?
For a 4-inch 10×10 slab you need about 56 × 80 lb bags, 75 × 60 lb bags, or 111 × 40 lb bags before waste — add roughly 10% on top. Because that's 50-plus bags, ready-mix delivery is usually cheaper and easier at this size.
How much does a 10x10 concrete slab cost?
A plain 4-inch 10×10 slab typically costs 800 installed at 8 per square foot, including material, labor, and basic site prep. Decorative finishes like stamping or staining can push it well past $1,200.
How thick should a 10x10 slab be?
Use 4 inches for patios and walkways, and 5–6 inches for driveways, garage floors, or anything bearing vehicle weight. Thicker slabs use proportionally more concrete — 6 inches needs 50% more than 4 inches.
How much does a 10x10 slab weigh?
A 4-inch 10×10 slab weighs about 5,000 lb (2.5 tons) — concrete runs roughly 150 lb per cubic foot. See how much concrete weighs for the full density tables.
Summary
- A 10×10 slab is 100 ft²; at 4 inches it needs 1.23 yd³ (order ~1.35 yd³ with waste).
- Thickness drives volume: 6 inches = 1.85 yd³, 50% more than 4 inches.
- In bags: ~56 × 80 lb for a 4-inch pour — but ready-mix wins above ~½ yard.
- Budget 800 installed for a plain finish.
Run your exact numbers — any size, thickness, and waste % — through the Slab Concrete Calculator.
Related Guides
- How to Calculate Concrete for a Slab (Formula + Examples)
- How Many Bags of Concrete for a Slab
- How Much Does a Concrete Slab Cost?
- How Much Does Concrete Weigh?
Visit Concrete Calculator Max for the full suite of slab and concrete estimation tools.
Related guides
- How to Calculate Concrete for a Slab (Formula + Examples)
Calculate concrete for any slab: Volume = Length × Width × Thickness ÷ 27. Worked examples, a thickness guide, waste allowance, and bags-vs-ready-mix.
- Slab Pouring Made Simple: How Many Concrete Bags You’ll Need
From 4-inch patios to garage floors — bag counts with examples.
- How Much Does a Concrete Slab Cost? (2026)
A concrete slab costs $4–$8 per square foot installed in 2026 — about $600 for a 10×10 and $7,200 for a 30×40. See cost by slab size, type, and finish.
Need a quick result? Try the related calculator.