How much does concrete weigh — a slab, a volume, or the broken-up debris from a demolition. Pounds, tons, kilograms and tonnes from an editable density, with a debris mode for dumpster sizing and disposal fees.
What are you weighing?
Reinforced ~150, plain ~145, lightweight mixes 100–120. Edit to suit.
Rubble occupies ~1.3–1.6× the solid volume; air gaps between pieces.
Tossed-in rubble typically runs ~75–95 lb/ft³ (about 1–1.3 tons per loose yard).
Volume × density only. Concrete density varies with mix, aggregate and reinforcement; rubble bulking varies with piece size and how it’s loaded — both fields are editable. Dumpster weight limits and disposal fees come from your hauler, not this tool.
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Weighing it or pouring it?
This page converts concrete volume to weight. If you’re figuring how much concrete to buy for a slab or footing, that’s the Concrete Calculator — yards and bags, not pounds.
How much does concrete weigh?
Normal-weight concrete runs about 145–150 pounds per cubic foot — roughly 145 for plain concrete and 150 with rebar in it — which puts a cubic yard at about 4,000 lb, almost exactly 2 US tons.
For a slab, volume is just length × width × thickness: a 20×10 ft patio at 4″ is 66.7 ft³, almost exactly 5 tons of concrete. Lightweight structural mixes (100–120 lb/ft³) and heavyweight mixes exist, so the density field is editable.
Concrete weight per yard and per square foot
All values computed from the density formula at 150 lb/ft³ (reinforced); at 145, scale down about 3%.
Quantity
Pounds
US tons
kg
1 cubic foot
150
0.075
68
1 cubic yard
4,050
2.03
1,837
1 ft² of 4″ slab
50
0.025
22.7
1 ft² of 6″ slab
75
0.0375
34
100 ft² of 4″ slab
5,000
2.5
2,268
How much does broken concrete weigh?
Breaking concrete doesn’t change its weight — only the space it takes up. A demolished 4″ slab still weighs the same ~50 lb per square foot it did in one piece; what changes is that the rubble, with air gaps between chunks, occupies roughly 1.3–1.6× the original solid volume. That’s why a loose cubic yard of rubble weighs only about 2,000–2,500 lb (75–95 lb/ft³) even though a solid yard is ~4,000 lb.
The broken mode gives you both numbers: the tonnage your hauler will charge for, and the bulked volume that determines how many containers it fills. If you’re instead looking at an existing rubble pile and want its weight, switch the volume input to the loose-pile option and the tool multiplies the pile volume by the loose density instead.
Sizing a dumpster for concrete debris
Concrete is so dense that containers hit their weight limit long before their volume limit — haulers commonly restrict heavy debris to 10-yard containers and around 10 tons. A 400 ft² driveway at 4″ is about 10 tons of debris on its own, so plan loads around tonnage, keep concrete separate from lighter debris, and get the limits from your hauler before booking.
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Frequently asked questions
How much does a yard of concrete weigh?
About 4,000–4,050 lb — roughly 2 US tons — at the typical 145–150 lb/ft³. Lightweight mixes can be 2,700–3,200 lb per yard.
How much does a 4-inch slab weigh per square foot?
4″ of concrete is ⅓ ft thick, so 1 ft² is ⅓ ft³ — at 150 lb/ft³ that’s 50 lb per square foot. A 6″ slab is 75 lb/ft². Multiply by your area for total weight.
Does concrete weigh less after it’s broken up?
No — the mass stays the same. What changes is the volume: rubble bulks up ~1.3–1.6× because of air gaps, so a loose yard of rubble weighs only ~1–1.3 tons even though a solid yard weighs ~2. Use the broken mode for both figures.
How many tons of debris from my slab?
Solid volume × density: a 20×20 ft patio at 4″ is 133 ft³ ≈ 10 tons of debris — and at a 1.4 bulking factor it’ll occupy about 7 loose cubic yards in the container.
Wet vs dry concrete — which weighs more?
Nearly the same. Fresh concrete is marginally heavier than cured because some mix water evaporates during curing, but the difference is a few percent at most — the density field covers it. The big variations come from aggregate type and reinforcement, not moisture.