Calculation methodology

The concrete calculator converts all dimensions to feet, calculates volume in cubic feet, and divides by 27 to report cubic yards.

Shape formulas

Waste and rounding

The selected waste percentage is added after base volume is calculated. Bag quantities are rounded up to whole bags because partial bags cannot normally be purchased. Displayed values may be rounded for readability while calculations retain additional precision.

Prices and yields

Material cost uses the price entered by the visitor. Bag-yield and ready-mix estimates are planning values, so users should confirm current product yield, supplier minimums, fees, and local prices before purchasing.

Gravel and aggregate

The gravel calculator uses rectangle length × width × depth or circle π × radius² × depth geometry. It divides cubic feet by 27, applies the additional loose-material compaction percentage first, then applies waste. Tons equal loose cubic yards multiplied by editable density. Bag quantity is rounded up once after converting total tons to pounds. Cost uses only the selected ton, cubic-yard, or bag price.

Preset densities are planning assumptions. Moisture, gradation, source, supplier measurements, product yield, and delivery minimums vary. Confirm assumptions before ordering; this calculator does not provide structural, drainage, or engineering advice.

Last reviewed: August 23, 2026.