Material calculators for DIY home & yard projects
How many gallons, boxes, bags or yards? HandyFigures answers the question every project starts with — with the math shown, whole-project shopping lists you can print, and no sign-up. Everything runs in your browser, and your project plans never leave your device.
Calculators
Paint Calculator
Work out how many gallons of paint you need across every room — walls, ceilings, trim and primer — and print one shopping list for the whole job.
Flooring Calculator
Calculate flooring boxes with waste built in for straight, diagonal or herringbone layouts, compare materials side by side, and print your order list.
Mulch & Soil Calculator
Convert beds and borders into cubic feet, cubic yards and bags of mulch, soil or gravel — then see whether buying bags or bulk delivery costs less.
Guides
Plain-language project math — coverage rates, waste percentages and bag-vs-bulk economics, each paired with a calculator.
How Many Bags of Mulch in a Cubic Yard? Bag vs Bulk Math
How many bags of mulch in a cubic yard? 13.5 two-cubic-foot bags — plus the bag-vs-bulk break-even math that decides which one to buy.
Ceiling Paint vs Wall Paint: Why the Math Is Different
Ceiling paint vs wall paint math explained: why length-times-width with no deductions, one coat, and a flat sheen change how many gallons you buy.
Do You Need Primer? How to Count It Separately From Paint
Do you need primer? Five wall conditions that demand it, three that skip it, plus the math for counting primer gallons separately from paint.
Do You Need Underlayment? Roll Math and When to Skip It
Do you need underlayment under laminate or vinyl plank? Quick answers on attached pads, concrete subfloors, and how many 100 sq ft rolls to buy.
How Much Extra Flooring to Buy: Waste % by Pattern
Flooring waste percentages by pattern: 10% straight, 15% diagonal, 20% herringbone — and where the waste actually goes, from end cuts to defect culls.
How Much Gravel for a Patio Base? Depth and Tonnage Math
Gravel for a patio base, worked step by step: cubic yards for a 10x20 at 4 inches, the 20–25% compaction allowance, and yards-to-tons math.
Why we built this
Every DIY project starts with the same uncomfortable guess at the store: is three boxes enough? Will two gallons cover it? Get it wrong in one direction and you're driving back mid-project with wet paint on the roller; get it wrong in the other and unopened boxes live in the garage for years. The big-box store calculators answer one room at a time and conveniently round up. HandyFigures does the arithmetic the way you'd do it on paper — whole project, real waste allowances, every step shown — so you can check the number instead of trusting it.
How it works
- Add your rooms or beds — the plan saves in your browser, so multi-weekend projects keep their numbers.
- Get quantities with the math visible, rounded the way stores actually sell things: gallons, quarts, boxes, bags, yards.
- Print one shopping list for the whole project. Nothing you type is uploaded — ever.