How CubicGauge Calculates Material Estimates

CubicGauge turns measured dimensions into a geometric quantity, then shows any optional ordering allowance as a separate step. These results are planning estimates, not engineering specifications.

1. Dimensions to area and volume

For rectangles, area is length multiplied by width. A circle uses π times radius squared. An L-shape is represented as two non-overlapping rectangles, and multiple areas are summed. US volume uses square feet × depth in inches ÷ 324 to get cubic yards. Metric volume uses square meters × depth in meters to get cubic meters.

2. Geometric quantity and order quantity

Geometric volume describes the measured shape and entered depth. Order quantity is geometric volume multiplied by one plus the allowance percentage. The allowance is optional and shown explicitly; it is not silently included in the geometric result.

3. Density and supplier data

Density depends on gradation, particle shape, voids, moisture, and how the material is handled. The values below are editable planning defaults used by current calculators, not universal specifications. A supplier or manufacturer value for the actual product takes precedence.

Material planning values

Supplier examples are product- and location-specific. For example, published pea-gravel and #57 weights differ between suppliers and from CubicGauge defaults. Use the actual product data or weigh-ticket conversion when available.

Concrete bag yields and density

QUIKRETE Concrete Mix No. 1101 lists approximate yields of 0.30 ft³ for 40 lb, 0.375 ft³ for 50 lb, 0.45 ft³ for 60 lb, 0.60 ft³ for 80 lb and 0.675 ft³ for 90 lb bags. Yields vary by product; the manufacturer's label or data sheet takes precedence.

Normalweight concrete is approximately 150 lb/ft³ (2400 kg/m³), according to ACI Concrete Terminology. Density varies by mix, so this is an editable planning estimate, not a product specification.

Sources: QUIKRETE Concrete Mix No. 1101 technical data · QUIKRETE calculator. Last reviewed: October 2, 2026. Ordering allowance is user-controlled. Concrete quantities here are estimates, not structural engineering specifications.

4. Bag yields

Volume bags use the entered labeled volume (the initial pea-gravel estimate is 0.5 ft³ per bag). Weight bags use their entered net weight and the selected planning density. Calculated bag requirements retain full precision; practical purchase counts round upward to whole bags. Check the label and actual fill before ordering.

5. Ordering allowance

The allowance is kept separate so you can see both the geometric quantity and the adjusted order quantity. It can be set to zero; it is not a mandatory waste factor or a hidden compaction estimate.

6. US and Metric units

Unit conversions use fixed physical conversion factors. The calculators convert user-entered measurements when the unit system changes so the physical dimensions remain equivalent. Density is converted between US tons per cubic yard and kilograms per cubic meter without changing its physical meaning.

7. Precision and display rounding

Calculations use unrounded intermediate values. Rounding is applied only for display, except whole-bag purchase counts, which are rounded up because partial bags are not normally sold.

8. Limits

Actual quantities can differ because of shape, uneven subgrade, compaction, moisture, handling, delivery minimums, product grading, or supplier measurement practices. Results are estimates, not engineering specifications. Verify project requirements and orders with the relevant supplier or qualified professional.

Use the Gravel Calculator, Pea Gravel Calculator, Driveway Gravel Calculator, Sand Calculator or Topsoil Calculator.