How much does a yard of concrete weigh?

A cubic yard of normal-weight concrete weighs about 3,900–4,050 pounds — roughly 2 short tons. The standard figure comes from a density of 145 lb/ft³ × 27 cubic feet per yard ≈ 3,915 lbs. Engineers commonly round to 4,050 lb/yd³ (150 lb/ft³) to add a small safety margin when sizing structure.

What is the difference between lightweight and normal-weight concrete?

Normal-weight concrete uses sand and gravel aggregate and weighs 140–150 lb/ft³. Lightweight concrete swaps in expanded shale, clay, or slate aggregate to drop the density to about 90–115 lb/ft³ — roughly 25–35% lighter. That weight reduction matters most on elevated decks, multi-story floors, and long-span beams, where lighter concrete means smaller, cheaper supporting members; the tradeoff is higher material cost and slightly lower strength per cubic foot.

How much does a full concrete truck weigh?

A loaded ready-mix mixer truck weighs around 60,000–70,000 lbs gross — roughly 30,000–34,000 lbs for the truck and drum plus 31,000–40,000 lbs for an 8–10 yard load of concrete. That is near the federal legal limit of 80,000 lbs for the whole rig, which is why plants rarely overfill. The concentrated axle load can crack residential driveways and rut soft lawns, so confirm the access route before scheduling delivery.

How much does a 4-inch concrete slab weigh per square foot?

A 4-inch slab weighs about 48.3 lbs per square foot (145 lb/ft³ × 0.333 ft), and a 6-inch slab about 72.5 lbs per square foot. This is the dead load the soil or supporting structure must carry — a 400 sq ft, 4-inch patio adds roughly 19,300 lbs to the subgrade. Use it as the starting dead load when checking whether a deck, beam, or footing can support a slab.

Does rebar change the weight of concrete?

Yes, but only slightly. Steel weighs about 490 lb/ft³ versus 145 lb/ft³ for concrete, but a typical reinforced slab is only 0.5–1.5% steel by volume, so rebar adds roughly 2–8 lbs per cubic foot — about 1–3% to the total. Engineers usually fold this into the standard 150 lb/ft³ design density rather than calculating the steel separately for ordinary slabs and footings.

Why does concrete weight matter for structural design?

Concrete weight is the dead load engineers use to size beams, slabs, columns, and footings — the permanent load the structure carries before any people, furniture, or snow (live load) is added. Underestimating it leads to undersized members and deflection or cracking; the ACI 318 standard density of 145 lb/ft³ (150 lb/ft³ for design) is the reference value. On elevated decks and floors, dead load drives nearly every member size, which is why lightweight mixes are specified to keep it down.

Concrete Weight Calculator — Pounds, Tons & Kilograms

Estimates the total weight of concrete for any pour volume — accounting for mix density.

How to Use This Concrete Weight Calculator

This concrete weight calculator converts a volume of concrete — in cubic yards, cubic feet, or cubic meters — to weight in pounds, short tons, and kilograms, using an editable mix density. Enter your volume in any unit to get the equivalent weight instantly, and adjust the density if you are pouring a lightweight or heavyweight mix. To find the volume first, use the concrete volume calculator.

Dead Load vs Live Load: Why Concrete Weight Matters

In structural engineering, the weight of the concrete itself is the dead load — the permanent, unchanging load a member carries before anything is placed on it. The live load is everything that comes and goes: people, vehicles, furniture, snow. Engineers size beams, slabs, columns, and footings to carry both, and on elevated decks and floors the concrete dead load is often the larger of the two. That is exactly why a designer might specify a lightweight mix at 110 lb/ft³ instead of 145 — shaving the dead load can shrink every supporting member and reduce cost.

For slab-on-grade, the same weight becomes a bearing problem. A residential slab imposes only 48–72 lbs per square foot, well under the 1,500–3,000 lbs per square foot bearing capacity of undisturbed soil — but loose fill, expansive clay, or poorly compacted subgrade can settle differentially and crack the slab. A 4-inch compacted gravel base spreads the load and improves drainage. For elevated structures, confirm the framing and footings can carry the slab weight with the deck footing concrete calculator.

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How Much Does Concrete Weigh?

Normal-weight concrete has a density of approximately 145 pounds per cubic foot (2,320 kg/m³). This is the standard density used in structural engineering and is what most ready-mix concrete suppliers deliver.

1 cubic foot of concrete = 145 lbs
1 cubic yard of concrete = 3,915 lbs (about 2 short tons)
1 cubic meter of concrete = 2,320 kg (2.32 metric tons)

Concrete Weight by Common Project Size

10×10 slab at 4 in thick (1.23 yd³) — approximately 4,814 lbs (2.4 tons)
20×20 driveway at 6 in thick (7.4 yd³) — approximately 28,970 lbs (14.5 tons)
Single 80 lb bag mixed — approximately 85–87 lbs cured

Types of Concrete and Their Densities

Not all concrete weighs the same. The type of aggregate used determines the final density:

Normal-weight concrete — 140–150 lb/ft³ (2,240–2,400 kg/m³) — standard mix with sand and gravel aggregate
Lightweight concrete — 90–115 lb/ft³ (1,440–1,840 kg/m³) — uses expanded shale, clay, or slate aggregate; used to reduce structural loads
Heavyweight concrete — 180–250 lb/ft³ (2,880–4,000 kg/m³) — uses dense aggregates like barite or magnetite; used for radiation shielding

This calculator uses the standard 145 lb/ft³ value for normal-weight concrete. If you are using a specialty mix, adjust your estimate accordingly.

Concrete Weight by Project Size

Understanding how much your pour will weigh helps with logistics planning, equipment rental, and structural design. Here are real-world weights for common residential and commercial projects using standard 145 lb/ft³ concrete:

Sidewalk (4 ft × 30 ft × 4 in) — 1.48 yd³ = approximately 5,800 lbs (2.9 tons)
Patio slab (12 ft × 16 ft × 4 in) — 2.37 yd³ = approximately 9,280 lbs (4.6 tons)
Two-car driveway (20 ft × 40 ft × 6 in) — 14.81 yd³ = approximately 58,000 lbs (29 tons)
Garage floor (24 ft × 24 ft × 5 in) — 8.89 yd³ = approximately 34,800 lbs (17.4 tons)
Basement slab (30 ft × 40 ft × 4 in) — 14.81 yd³ = approximately 58,000 lbs (29 tons)

A standard ready-mix truck carries about 10 cubic yards (39,150 lbs of concrete). Any pour over 10 yd³ requires multiple loads — plan the schedule accordingly. To calculate the volume for your specific project, use the concrete slab calculator.

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Transport, Axle Limits and Equipment Loads

Weight constrains how concrete gets to and around a job site. A loaded mixer truck runs 60,000–70,000 lbs gross — truck plus drum (about 30,000–34,000 lbs) plus the load — which sits close to the federal 80,000 lb limit, so plants size loads to stay legal on the axles rather than to fill the drum. That concentrated weight will crack thin residential driveways and rut soft lawns, so verify the route and stay clear of septic tanks and buried utilities before delivery day.

The same numbers govern lifting and placing. Precast panels, lintels, and pavers are heavy: a single cubic foot of normal-weight concrete is 145 lbs, so a modest 2 ft × 4 ft × 4 in precast cap already weighs nearly 390 lbs. Cranes, forklifts, and scaffolding all carry rated safe working loads — never exceed them, and confirm the volume and resulting weight of any precast element with the concrete volume calculator before rigging it.

Sources & References

ACI 318-19: Building Code Requirements for Structural Concrete — American Concrete Institute
PCA: Design and Control of Concrete Mixtures (16th Edition) — Portland Cement Association
ASTM C94/C94M: Standard Specification for Ready-Mixed Concrete — ASTM International

Concrete Weight Calculator