Last updated: 8/3/2026
Estimates only
Every calculator on this site — concrete, gravel, lumber, drywall, paint, and roofing — produces an estimate based on standard industry formulas and the values you enter. Results are intended as a starting point for planning and material ordering, not as final, guaranteed quantities.
Not professional or engineering advice
Nothing on this site constitutes structural, engineering, architectural, or legal advice. Construction projects involve site-specific conditions, local building codes, and safety requirements that a calculator cannot account for. Always consult a licensed contractor, structural engineer, architect, or your local building department for anything load-bearing, structural, or code-related.
Material figures vary by supplier
Densities (gravel), coverage rates (paint), yield (concrete bags), and similar figures used in these calculators are based on commonly published industry averages. Actual figures vary by manufacturer, product line, and regional supplier — always confirm exact figures with your supplier's spec sheet before finalizing an order.
No liability for reliance on results
We make reasonable efforts to keep the formulas on this site accurate, but we do not guarantee the accuracy, completeness, or suitability of any calculator result for your specific project. Use of these calculators, and any decisions made based on their output, is at your own risk. See our Terms of Use for the full limitation of liability.
Third-party content
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Questions
If you believe a calculator is producing an incorrect result, please tell us — email webdev08@protonmail.com with the calculator name and the inputs you used.