Free Construction and Home Improvement Calculators
Estimate materials and costs for your next project. Every calculator is built from original sources and shows the formula behind the result.
Browse project typesBrowse by project
Pick a project area to see all of its calculators.
Roofing
Roof pitch, roof area, rafters, and replacement cost.
View calculatorsDrywall
Sheets, joint compound, and installation cost.
View calculatorsPainting
Paint quantity, coverage, and painting cost.
View calculatorsFlooring
Square footage and flooring estimates.
View calculatorsConcrete
Slab cost, block count, cubic yards, and bags.
View calculatorsPopular calculators
Our most-used tools for measuring, materials, and costs.
Sheetrock Calculator
Drywall sheets, joint compound, and cost.
Square Footage Calculator
Area of rooms and common shapes.
Roof Pitch Calculator
Pitch, angle, and slope of a roof.
Roof Calculator
Roof area and material estimate.
Rafter Calculator
Rafter length and cut angles.
Roof Replacement Cost
Estimate the cost of a new roof.
Drywall Installation Cost
Material and labor estimate.
Paint Calculator
Gallons needed and coverage.
Why use Calctoolz
Simple tools you can check and trust.
Clear formulas
Each calculator explains the formula it uses, so you can follow the math yourself.
Original sources
Formulas are researched from original sources first, then built into the calculator exactly as defined.
Works on any device
Fast, simple tools that run well on phones, tablets, and desktops, with no sign-up.
How it works
Three steps from measurements to a material list.
- Choose a calculatorPick the project type you are working on.
- Enter your measurementsAdd your sizes and options in the units you use.
- Get your resultSee the estimate and the formula behind it.
Frequently asked questions
Are the calculators free?
Yes. All calculators are free to use and need no account.
How accurate are the results?
Results are estimates for planning, based on standard formulas. Always confirm your measurements and local requirements before buying materials or hiring a contractor. See our Disclaimer.
Do you store my measurements?
No. Calculator inputs are processed in your browser and are never sent to our servers or stored.
Can I suggest a calculator?
Yes. Email contact@calctoolz.com or use our contact page with the calculator you need.
Built and maintained by Shivam. Learn more about Calctoolz.