Geometry and exact conversions
Rectangle area = length × width. Circle area = π × (diameter ÷ 2)². For a known area, use the entered square footage or square meters directly. Volume = area × depth. We use 12 inches per foot, 27 cubic feet per cubic yard, 0.3048 meters per foot, and 0.764554857984 cubic meters per cubic yard.
Allowance
We sum measured volumes first, then multiply by 1 + allowance ÷ 100. The default 5% is an editable planning assumption. It is not a universal waste or compaction specification. Set it to 0% for measured volume only.
Weight and bags
Estimated gravel weight in US short tons = order volume in cubic yards × density in US tons per cubic yard. The 1.4 starting density is illustrative, not a sourced specification for every aggregate. Whole mulch bags = ceiling(order volume in cubic feet ÷ bag volume in cubic feet).
Price and rounding
The main dimension calculators show material-only cost. The separate bags-versus-bulk comparison includes the entered delivery charges, applies a minimum delivered order and rounds up to a supplier increment. It reports surplus and the break-even bulk delivery fee. Taxes must be included consistently in entered prices or left out of both. Material cost uses unrounded volume or weight, or the whole bag count, multiplied by the price you enter. Results display up to three decimal places for cubic yards and two for most other values. Extremely small values may display as zero after rounding; these tools are intended for landscaping quantities. Currency is USD. The main dimension calculators exclude supplier order increments, taxes, delivery and labor; the separate purchasing worksheets include only the prices and order rules you enter.
Density and purchasing tools
The guide converter supports both volume-to-weight and weight-to-volume calculations. One US short ton equals 907.18474 kg; one metric tonne equals 1,000 kg. A density in kg/m³ is multiplied by 0.764554857984 and divided by 907.18474 to obtain US tons per cubic yard. The buying comparison uses whole bags, then max(required bulk volume, minimum volume), rounded upward to the order increment. Break-even bulk delivery = total bag option minus bulk material cost. A negative result means bulk material already costs more.
Gravel quote comparison
Both suppliers are compared against the same required loose volume. Each supplier has a separate confirmed loose bulk density for weight conversion; volume-priced quotes do not depend on density. Confirm product suitability separately: equal volume and lower cost do not establish equal material quality. Convert that volume to each selected sales unit, apply the minimum delivered quantity, then round upward to its increment. Material charge is the larger of quantity × unit price and the minimum material charge. Add the entered delivery and other fees. A minimum charge changes the bill without adding material. Surplus uses the actual ordered quantity converted back to cubic yards. US short tons and metric tonnes are distinct. No automatic allowance, truck capacity or trip calculation is included.
Editorial approach and corrections
Our guides combine original calculation examples with clearly linked references for external material guidance. Illustrative densities and prices are labeled as assumptions; they are not supplier quotes or field measurements. Examples and tool calculations are checked with automated tests and worked arithmetic. We do not claim a professional site inspection or engineering review. Send corrections with the page URL, inputs and expected result to [email protected]. The gravel comparison was updated October 26, 2026 to use separate supplier densities and provide a printable calculation record.
Checks and limitations
The calculation engine is tested against exact conversions, multiple areas, circular geometry, bag rounding, allowances and invalid values. Measurements and material density still determine real-world accuracy. Shape simplification and ground variation can create differences between this estimate and the actual order.
Unit definitions: NIST conversion tables. Try the weight converter or purchase comparison.