Concrete Weight Calculator
Cured-slab pounds and tons for any volume
What is concrete weight calculator?
A concrete weight calculator answers a different question from the bag-count and yardage calculators most homeowners use. This tool tells you how much finished, cured concrete weighs for a given volume — the number you need for permitting, dead-load structural calcs, demolition planning, or vehicle/trailer load planning. It is not a wet-mix or bag calculator.
The density used is 150 lb/ft³ — the industry standard for normal-weight cured concrete, found in every structural load table and reinforced-concrete reference. This value applies to slabs, footings, walls, columns, and any cured concrete with conventional aggregate (gravel and sand). Lightweight concrete with expanded-shale aggregate runs 90-115 lb/ft³ and isn’t the right default for most residential or commercial work.
Use cases. For permitting, dead-load contribution from concrete slabs and footings is a routine line item — a 4-inch slab weighs 50 lb/ft², a 6-inch slab 75 lb/ft². For demolition planning, slab tear-out weight maps directly to dumpster sizing and disposal cost; most rental dumpsters cap at 8-12 tons per pull, so a 600 ft² driveway tear-out at 30,000 lb often needs two pulls or a heavier-rated roll-off. For vehicle load planning, knowing the weight of a precast piece (countertop, planter, slab section) before lifting saves real damage to trucks and trailers.
The math. Length × width × thickness gives volume in cubic feet; multiply by 150 lb/ft³ to get total pounds. Divide by 2,000 for short tons. Divide by 27 if you want cubic yards (since suppliers occasionally quote cured-state weights per yard for transport planning — about 4,050 lb/yd³).
Reinforcement adjustment. Mesh and #4 rebar at typical residential spacing add about 1% to slab weight; structural footings with #5/#6 bar can add 3-5%. For most residential dead-load calcs the contribution falls within the safety factor and gets ignored. For engineered structural designs, add it explicitly using the rebar’s published linear weight (~1.0 lb/ft for #4, ~1.5 lb/ft for #5).
What this tool is not for. Bag count for a fresh pour — see the concrete-bag-calculator, which incorporates wet-mix yields and water content in ways the cured-density math doesn’t. Dry pre-mix volume — different math. Concrete order in cubic yards from a ready-mix truck — same volume math, but the weight here is the delivered weight, not the placed (still-wet) weight that varies with slump and entrained air.
When to use a concrete weight calculator
- Permit and structural-load calcs — Dead-load contribution of a concrete slab or footing on a structural design. Output in pounds matches load-table units.
- Demolition planning — Estimate dumpster size and disposal cost for a slab tear-out. Output in tons matches dumpster-rental tonnage limits.
- Trailer and truck load planning — Determine whether a concrete piece (countertop, planter, slab section) fits within a trailer or truck weight rating.
How to use the Concrete Weight Calculator
- Measure the slab or footing — Multiply length by width by thickness. For irregular shapes (L-shaped slabs, stepped footings), break the geometry into rectangles and add the partial weights.
- Confirm cured-state assumption — This calculator uses 150 lb/ft^3 — the density of cured normal-weight concrete. Wet-mix bag yields are different math entirely (see the concrete-bag-calculator). Use this tool for finished, hardened concrete only.
- Read pounds and tons — Output shows total pounds and short tons. For permitting and load tables, pounds is the standard unit. For demolition quotes and dumpster sizing, tons matches industry billing.
- Add reinforcement weight if needed — Rebar and mesh add roughly 1-2% to slab weight (more for heavily reinforced footings). For most residential dead-load calcs, this is within the safety factor; for engineered designs, add it explicitly.
Worked examples
Garage slab, 20 ft x 24 ft x 4 in
Input: 20 ft x 24 ft x 4 in depth
Output: 24,000 lb / 12.0 tonsPatio tear-out, 12 ft x 16 ft x 4 in
Input: 12 ft x 16 ft x 4 in depth
Output: 9,600 lb / 4.80 tonsA 20-yard demolition dumpster typically allows 8-10 tons — plan a second pull or a heavier-rated container.
Strip footing, 1 ft x 50 ft x 8 in
Input: 1 ft x 50 ft x 8 in depth
Output: 5,000 lb / 2.50 tons