Free · Inputs shown · Check each tool's limits
Calculators that show their work.
Free tools for home improvement projects. See the formulas, assumptions, and source references behind each estimate.
Where to start · by what you're building
Tell us the project, not the tool.
Building a deck
Redoing a room
Concrete + masonry
Heating, cooling + power
Shows the formula
Check each tool's stated inputs, assumptions, units, and calculation steps before applying an output to your project.
Check product details
Use current coverage information for the exact product and application. Do not treat an example rate as a product specification.
Planning arithmetic
Rounding and package sizes vary by tool and product. Confirm the purchase unit shown and verify it with the supplier before ordering.
Or start typing your project50 TOOLS · 8 CATEGORIES
Before you buy · compare the project details
Buying guides
All guides →Vinyl vs fiber cement siding
Compare product specifications, installation scope, maintenance, and local bids.
Composite vs PT vs cedar decking
Compare exact products, maintenance instructions, warranties, and complete project quotes.
Heat pump vs furnace + AC
Compare heating options by climate, local energy rates, and installed quotes.
Formulas and assumptions should be open to inspection. Each calculator shows its arithmetic and relevant references. Estimates depend on the inputs and stated limits; code-dependent and safety-critical decisions need local professional review. transparency isn't a feature, it's the whole point.