How our estimates work
Our calculators turn your measurements into practical quantities using visible formulas and clearly labeled assumptions.
Measurements and units
The MVP accepts U.S. customary measurements. Lengths are converted to feet before area and volume calculations. Area is calculated in square feet, volume in cubic feet, and bulk volume in cubic yards using exactly 27 cubic feet per cubic yard. Weight and liquid conversions are used only where the individual calculator calls for them.
Full precision, readable results
Calculations retain normal JavaScript numeric precision internally. We round only for display, choosing a small number of decimal places that is useful for purchasing. Whole-bag and whole-gallon recommendations round upward because partial packages may not be purchasable. This avoids showing misleading fake precision.
Calculated amount and purchase recommendation
The calculated amount comes directly from the dimensions and formula. The recommended purchase amount applies the buffer or waste percentage selected by the user:
Recommended amount = calculated amount × (1 + buffer percentage ÷ 100)
A default is a planning convenience, not a universal rule. You can change it, including setting it to zero.
Variable assumptions
Some outputs depend on information that is not fixed. Gravel weight appears only when supplier or material density is entered. Grass seed uses the new-lawn or overseeding application rate from the selected product. Topsoil bag counts use optional product bag volume, and paint uses measured openings area plus editable coverage. Concrete bag equivalents use approximate common yields supported by the QUIKRETE Concrete Mix No. 1101 technical data sheet. Product labels and local suppliers should take precedence over planning defaults and comparison values.
Three levels of estimate accuracy
We separate exact math from variable inputs: geometry and unit conversions are calculated directly, supplier-specific values come from the product or supplier when available, and editable percentages or depths remain user-selected planning allowances. In short: exact math → supplier-specific values → user-selected planning allowances.
Why the real amount may differ
Measurement error, irregular shapes, slope, grade, compaction, settlement, moisture, spills, surface texture, application method, and product variation can all affect material use. A calculator is a planning tool—not a site inspection, quote, engineering design, code review, or professional recommendation.