Sources & Data
The references below were checked on September 11, 2026. Product and supplier values can change: always confirm the current specifications for your project.
Measurement, materials and manufacturer references
- NIST Handbook 44 — unit-conversion reference, including the exact cubic relationship used by volume tools. NIST current edition.
- Caterpillar material density tables — optional loose-density references for gravel and topsoil. Supplier density overrides a convenience reference. Caterpillar reference tables.
- Penn State Extension — Lawn Establishment — source-labeled grass-seed rate ranges used by the grass-seed calculator. Penn State Extension.
- Virginia Tech Extension — reference demonstrating that sod pallet coverage can vary; supplier coverage is therefore required for unit counts. Virginia Tech Extension.
- USG Sheetrock installation guide — common 4 × 8, 4 × 10 and 4 × 12 ft drywall sheet-size presets. USG guide.
- ENERGY STAR insulation guidance — R-value guidance showing why insulation requirements vary with climate and building location. The insulation calculator therefore does not invent a universal R-value. ENERGY STAR R-value guidance.
- Greenfiber SANCTUARY coverage chart — manufacturer example showing that maximum square feet per bag and installed depth vary by target R-value. The blown-in insulation calculator therefore requires the exact chart value for the selected product/R-value. Greenfiber coverage data.
- Sherwin-Williams paint quantity guidance — measure paintable surfaces, subtract major openings and use the selected product's label coverage; actual requirements can vary with application and surface condition. Sherwin-Williams guidance.
- Tile Council of North America — grout-joint guidance explaining why one universal joint width is not appropriate for every installation. The tile calculator therefore does not hide a fixed joint-width assumption. TCNA grout guidance.
- Trex deck planning calculator — separates dimensions, substructure and decking and highlights the safety importance of the framework. The ProjectCalcWorks deck tool therefore estimates decking only, not structural framing. Trex deck planning calculator.
- Asphalt Institute engineering FAQ — asphalt-quantity guidance calculates cubic feet from area and thickness, then converts volume to weight. It states asphalt mixture typically weighs 142–148 lb/ft³ in place and uses 148 lb/ft³ in its estimating example. ProjectCalcWorks keeps this density visible and editable. Asphalt Institute engineering FAQ.
What is intentionally not a universal preset
Mulch bag volume, sod unit coverage, flooring/tile box coverage, paint coverage, blown-in bag coverage, decking dimensions, paver base depth, fence layout values and similar product/project details are not hard-coded as national facts. Enter the value from the exact product, supplier or plan you are using.
Grass-seed presets are source-labeled ranges rather than a single rate. Gravel and topsoil densities are optional references for approximate weight conversion; volume remains the primary calculation.
Source precedence
When a current manufacturer label, supplier specification, project document or applicable local requirement conflicts with a general convenience reference on this site, use the project-specific source. Report outdated references through Contact.