How we calculate
Geometry is exact. Everything else on this page is a published industry figure with a real-world range, and every one of them can be changed on the calculator itself.
Last reviewed September 19, 2026
Material quantity maths has two halves. The first is volume, which is fixed: an area times a depth, converted between units with exact factors. The second is what that volume weighs or how far it spreads, which varies by source, moisture and how hard the material is compacted. This page lists the second half in full.
Verification status: checked September 19, 2026. Concrete bag yields come straight from the manufacturer data sheet and match ours exactly. Material weights are cross-checked against two independent published tables. Paint spread rates sit inside the band the major paint brands print. Every source is named at the foot of this page, and where a figure is an industry consensus rather than a manufacturer statement, it says so.
Material weights
Loose, as-delivered weights. Suppliers sell aggregate and soil by the ton, so these turn your volume into an order. Compacted weights are higher, and wet material is heavier than the same material dry.
| Material | lb per ft³ | Typical range | US tons per yd³ | Note |
|---|---|---|---|---|
| Crushed stone / #57 gravel | 110 | 104–126 | 1.49 | About 1.5 US tons per cubic yard, within the 1.4–1.7 ton range published for ¼–2 in gravel. Wet stone weighs more. |
| Crusher run / road base | 118 | 110–126 | 1.59 | Contains fines, so it packs tighter and weighs more than clean stone: roughly 1.6 tons per cubic yard. |
| Pea gravel | 102 | 93–111 | 1.38 | Rounded stone, about 1.375 tons per cubic yard (published range 1.25–1.5 tons). |
| River rock | 93 | 81–104 | 1.26 | Larger 2–6 in stone, about 1.25 tons per cubic yard (published range 1.1–1.4 tons). |
| Sand (dry) | 104 | 96–111 | 1.40 | Dry loose sand, about 1.4 tons per cubic yard. Wet sand runs 1.5–1.7 tons. |
| Screened topsoil | 81 | 74–96 | 1.09 | About 1.1 tons per cubic yard dry (published range 1–1.3 tons). Wet topsoil reaches 1.5–1.7 tons. |
| Compost | 44 | 35–60 | 0.59 | Roughly 1,200 lb per cubic yard, lighter than topsoil. |
| Bark or wood mulch | 22 | 15–30 | 0.30 | About 600 lb per cubic yard dry; rain can double it. |
| Concrete (normal weight) | 150 | 140–155 | 2.02 | Standard figure for normal-weight ready-mix: about 4,050 lb (2 tons) per cubic yard. Bagged mix cures a little lighter, around 140 lb/ft3 (3,780 lb per yard). |
| Hot mix asphalt | 145 | 140–150 | 1.96 | Compacted hot mix, roughly 2 tons per cubic yard. Mix designs vary. |
Bag yields
Concrete bag yield is the volume of mixed concrete a bag makes, not the volume of dry powder.
- 80 lb concrete mix0.6 ft³
- 60 lb concrete mix0.45 ft³
- 50 lb concrete mix0.375 ft³
- 40 lb concrete mix0.3 ft³
- 2 cu ft (mulch, soil, stone)2 ft³
- 3 cu ft (mulch, soil, stone)3 ft³
- 1.5 cu ft (mulch, soil, stone)1.5 ft³
- 0.5 cu ft (mulch, soil, stone)0.5 ft³
It takes 45 eighty-pound bags to make one cubic yard of concrete, or 13.5 two-cubic-foot bags to fill a cubic yard with mulch.
Paint coverage
Square feet per US gallon, per coat. Check the can: manufacturers print their own rate.
- Smooth drywall or plaster400 sq ft/gal
- Light texture or previously painted350 sq ft/gal
- Heavy texture, stucco or masonry275 sq ft/gal
- Primer / sealer250 sq ft/gal
- Door deducted from wall area21 sq ft
- Window deducted from wall area15 sq ft
Conversion factors
- Cubic feet in a cubic yard27
- Square feet in a square metre10.7639
- Square feet in a square yard9
- Square feet in an acre43,560
- Pounds in a US ton2,000
Waste allowances
Defaults only. Every calculator lets you change the percentage.
- Concrete10%
- Gravel, stone and sand10%
- Mulch and soil (settling)5%
- Tile and flooring cuts10%
Rounding always goes up for anything sold as a whole unit: bags, cans and pieces.
Where these figures come from
Checked September 19, 2026. Primary means the manufacturer or supplier states the number itself; consensus means several independent published tables agree on it.
- QUIKRETE Concrete Mix data sheet No. 1101Primary
Bag yields for mixed concrete: 40 lb makes 0.30 ft³, 50 lb makes 0.375 ft³, 60 lb makes 0.45 ft³ and 80 lb makes 0.60 ft³. These are the exact figures the concrete calculator uses. The same sheet gives fresh bagged mix a density of about 140 lb per cubic foot.
- Sakrete concrete placement guidancePrimary
Forty-five 80 lb bags make one cubic yard, and one cubic yard placed 4 inches deep covers 81 square feet. Both agree with our arithmetic to the bag and the square foot.
- Inch Calculator and calculator.net material tablesConsensus
Loose delivered weights for crushed stone, crusher run, pea gravel, river rock, sand, topsoil, compost and bark mulch, plus 150 lb per cubic foot for normal-weight concrete. Checking against these tables is what caught five of our aggregate weights being too light.
- Sherwin-Williams, Benjamin Moore, Behr and PPG published spread ratesConsensus
All four print 350–400 square feet per gallon per coat on smooth, primed drywall. We use 400 only for genuinely smooth sealed walls and default to 350, which is what most rooms actually take.
- NIST Handbook 44 / international yard and pound agreementPrimary
Every unit conversion: 27 cubic feet to the cubic yard, 10.7639 square feet to the square metre, 43,560 square feet to the acre and 2,000 lb to the US ton. These are exact by definition, not estimates.
What these calculators do not do
- They size quantities, not structures. Slab thickness, reinforcement and footing design come from an engineer or your local code.
- They do not price materials for you. Any cost shown uses the price you typed in.
- They assume the measurements you enter are correct. Measure twice, especially depth, which is where most ordering mistakes start.