How much does a 4×4 concrete slab weigh?
A 4 × 4 ft concrete slab 4 inches thick holds 5.33 cubic feet and weighs about 773 pounds at 145 pounds per cubic foot. At 6 inches thick it is about 1,160 pounds.
How to work it out
- 4 ft × 4 ft × 4 in = 5.33 cu ft
- 5.33 cu ft × 145 lb/cu ft = 773 lb (0.39 tons)
People ask this for two reasons: they want to move an old AC or grill pad, or they want to know what a new one will put on the ground. Either way, it is far more than it looks.
Adjust for your project
- Weight in short tons
- 0.39 tons
- Weight per square foot of slab
- 48.3 lb
- Volume
- 0.2 cu yd (5.33 cu ft)
- Unit weight used
- 145 lb/cu ft (3,915 lb/cu yd)
4×4 slab by thickness (145 lb/cu ft)
| Thickness | Weight | Weight per square foot of slab |
|---|---|---|
| 2 in | 387 lb | 24.2 lb |
| 3.5 in | 677 lb | 42.3 lb |
| 4 in | 773 lb | 48.3 lb |
| 5 in | 967 lb | 60.4 lb |
| 6 in | 1,160 lb | 72.5 lb |
Moving a 4×4 pad
At roughly 770 lb, a 4 × 4 pad is beyond what a few people should try to lift. It can be levered and walked on steel pipe rollers, or broken up with a sledge or rented breaker into pieces you can carry — a 1 × 1 ft chunk of a 4 in slab is still about 48 lb. If it was poured with mesh, cut the wire as you go. Cutting concrete makes silica dust; OSHA’s rule for saws is to use a saw with water fed continuously to the blade.
A new pad of this size is about ten bags of 80 lb mix with a little spare — see how many bags of concrete for a 4×4 slab. Precast patio pads of the same footprint are thinner and lighter, which is why many equipment pads are now plastic or lightweight composite.
Other small pads
Weight scales with area: a 3 × 3 ft pad at 4 in is about 435 lb, a 3 × 4 about 580 lb, and a 5 × 5 about 1,210 lb. The per-square-foot figure for any thickness is on concrete weight per square foot.
Different size? Use the full Concrete Weight Calculator.
What you’ll need
- Nitrile-coated work glovesBudget price
Wet concrete and mortar are caustic. Keep the cement off your skin with waterproof gloves, and wash off any that gets in.
See options on Amazon (opens in a new tab) - Safety glassesBudget price
Splashes of wet concrete and chips from cutting block both go for the eyes.
See options on Amazon (opens in a new tab) - Contractor wheelbarrowMid-range price
A 6 cu ft steel or poly tray with a pneumatic tire moves concrete from the mixer to the forms. Never load it to the brim with wet concrete.
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Frequently asked questions
How much does a 4×4 slab 6 inches thick weigh?
About 1,160 pounds at 145 pounds per cubic foot.
How much does a 3×3 concrete pad weigh?
About 435 pounds at 4 inches thick.
How much does a 5×5 concrete slab weigh?
About 1,208 pounds at 4 inches thick.
Other common sizes
- How much does a yard of concrete weigh — About 3,915 lb (140–150 lb per cu ft)
- How much does a cubic foot of concrete weigh — About 145 lb (140–150 lb range)
- Concrete weight per square foot — 48.3 lb per sq ft at 4 in thick
Sources
- Iowa DOT Instructional Memorandum 340 — Weight per cubic foot, yield and air content of concrete (opens in a new tab) — Normal-weight concrete is typically 140–150 lb per cu ft at 5 to 8 percent air.
- Quikrete Concrete Mix (No. 1101) data sheet (opens in a new tab) — Yields: 40 lb ≈ 0.30, 50 lb ≈ 0.375, 60 lb ≈ 0.45, 80 lb ≈ 0.60, 90 lb ≈ 0.675 cu ft; unit weight ≈ 140 lb/cu ft; for pours 2 in thick or more; 6–9 pints of water per 80 lb bag; control joints every 6–8 ft; cure 5 days at 70 °F or above, 7 days at 50–70 °F; protect from freezing for 48 hours.
- NRMCA Concrete in Practice 31 — Ordering Ready Mixed Concrete (opens in a new tab) — Truck mixers carry 8 to 12 cubic yards (about 6 to 9 m³); order 4–10% more than the plan estimate; a loaded truck weighs about 80,000 lb; fresh concrete can cause severe chemical burns.
- NIST Handbook 44, Appendix C — General Tables of Units of Measurement (opens in a new tab) — 1 cubic yard = 27 cubic feet; 1 cubic foot = 1,728 cubic inches.