ProjectCalcly is a free collection of home improvement and construction calculators. Our goal is simple: help homeowners, DIYers and tradespeople work out how much material a project needs, quickly and accurately, without spreadsheets or guesswork.
Why We Built ProjectCalcly
Most people only pour a slab, tile a bathroom or replace a roof a few times in their lives. When they do, they face confusing units such as cubic yards, roofing squares, BTU and kilowatt-hours, and a lot of calculators online give a single number with no explanation. We wanted tools that show their working, support both imperial and metric units and explain what to buy in plain language.
What You Will Find Here
- Concrete & masonry calculators for slabs, footings, blocks, gravel, mulch and topsoil.
- Flooring & wall calculators for flooring, tile, paint, drywall and wallpaper.
- Roofing & outdoor calculators for roofs, roof pitch, fences and decks.
- HVAC & energy calculators for air conditioner sizing and solar panels.
How Our Calculators Are Built
Every calculator is built on standard geometric formulas and widely published industry conventions, such as the yield of a bag of pre-mixed concrete, the coverage of a gallon of paint, the size of a standard drywall sheet and the definition of a roofing square. On each page we show the formula we use, a worked example and the assumptions behind the result, so you can check the numbers yourself.
Before a calculator goes live, we test it against hand-worked examples in both imperial and metric units, check edge cases such as very small or very large inputs, and make sure it works on phones, tablets and desktops. When product standards change or a reader reports an issue, we review and update the tool.
Our Principles
- Free and open to everyone. No sign-up, no paywalls and no limits.
- Transparent. We show formulas and assumptions instead of hiding them.
- Private. Calculations run in your browser and your inputs are not stored.
- Practical. Results are given in the units you actually buy: bags, boxes, sheets, bundles, rolls and panels.
A Note on Professional Advice
Our calculators are planning tools. They are not a substitute for a site visit, engineering advice or a quote from a licensed contractor. For structural, electrical, roofing, HVAC and solar work, always follow local codes and consult a qualified professional. Please read our disclaimer for details.
Get in Touch
Found an error, have a suggestion or want us to build a new calculator? We read every message. Visit our contact page or email us at contact@projectcalcly.com.