DIYCalcs is a set of free, no-signup calculators for home improvement and yard projects. The goal is simple: help you buy the right amount of material the first time.
How the calculators are built
- Published data only. Bag yields, coverage rates, code limits and sizing charts come from manufacturers, the International Residential Code, ENERGY STAR and university extension services. Each calculator page lists its sources.
- Formulas you can check. Every page explains the math, with worked examples.
- Tested. The calculation code is covered by automated tests against hand-worked examples.
- Private. The calculations run in your browser. We don't store the measurements you type.
Sources we rely on
- Quikrete Concrete Mix (No. 1101) data sheet – yield per bag
- Quikrete Fast-Setting Concrete Mix spec data sheet
- ENERGY STAR – Room air conditioner sizing chart
- 2021 International Residential Code, Section R311.7 – Stairways
- 2021 International Residential Code, Section R905.2 – Asphalt shingles
- USG – How much joint compound do I need?
- USG Sheetrock® Wallboard Estimator
- University of Illinois Extension – Proper mulching techniques
- University of Nebraska–Lincoln Extension – Mulch (EC1274)
- UF/IFAS Florida-Friendly Landscaping – Mulch
- Sherwin-Williams – Paint calculator
- Unilock – Paver base preparation
- Fine Homebuilding – Estimating materials for roofing projects
- Bob Vila – How to install fence posts
- NIST Handbook 44 – Unit conversions
Photos
Photos are from Unsplash, used under the Unsplash License.
Limitations
The results are estimates for planning and shopping. Real products, soils and buildings vary. For structural work, permits and code questions, your local building department has the final word.
Contact
Found an error or want a new calculator? Write to juanfersem@gmail.com. Corrections are reviewed and published with an updated review date.
Last reviewed November 2, 2026.