About HandyFigures
HandyFigures publishes free material calculators for home and yard projects and reference pages on what it costs to run a home, with the math behind every answer.
Why this exists
A stressful moment in many DIY projects is standing in the store aisle and guessing quantities. The calculators the big retailers offer often answer one room at a time, hide their assumptions, and round up. The same is true of household running costs: electricity prices, bills and appliance costs are published by the U.S. Energy Information Administration and the Department of Energy, but rarely in a form you can use at the kitchen table. HandyFigures does both jobs with the working shown.
What you'll find here
- Material calculators for paint, flooring and mulch, soil and gravel, with whole-package rounding and a printable shopping list.
- Home energy costs built on federal data: the average electric bill in every state, current residential electricity rates, the cost to run common appliances and the cost to charge an EV at home.
- Project guides for paint, flooring, mulch and soil jobs. Browse all guides.
How we build our calculators
- Show the math. Every tool explains its formula, exposes project assumptions as editable inputs, and separates exact conversions, such as 27 cubic feet per cubic yard, from values that must come from a product label, supplier or measured site. You can check the result with a pencil.
- Run everything in your browser. The calculators are 100% client-side. Your room sizes and prices are never uploaded, logged or sold. Saved projects live in your own browser's storage.
- Round like the store sells. Gallons and quarts, whole boxes, whole bags. An estimate you can't buy isn't an estimate.
- Stay inside our lane. We do quantities and costs. How to build, wire, plumb or structure something is a different kind of question, and we say so rather than guess.
Who runs it
HandyFigures is an independent site run by a small publishing team. Guides carry the editorial byline Sam Whitaker, a pen name the team uses for its writing and editing. We are not a retailer and we don't sell materials or energy plans, so we have no reason to round your order up or steer you to a supplier. If a calculator gives a strange answer or a guide gets something wrong, tell us.
How we research, cite and correct our guides
Coverage rates, product limits and safety guidance come from manufacturer data sheets, university extension services and federal agencies, and each guide links the sources it used. Energy figures come from the U.S. Energy Information Administration, the Department of Energy, ENERGY STAR and fueleconomy.gov, and each table states its data period, such as the EIA month or year it covers.
Worked examples use sample measurements and round numbers so the arithmetic is easy to follow; replace them with your own measurements or use the matching calculator. Where a product's label or a supplier gives a different figure, the label wins.
To report an error, email us from the contact page with the page address, what looks wrong and, if you have one, the source that shows the correct figure. Confirmed corrections are made on the page and reflected in its update date.
How we keep it free
The site is free to use and does not require an account. We intend to support it with display advertising (Google AdSense); ads are not switched on yet, and we do not use affiliate links. When that changes, the ad and affiliate disclosure and privacy policy will be updated first.