Home improvement calculators & cost estimators

By the LocalServiceHQ editorial team
Formulas and sources shown on each tool
Updated Oct 28, 2026

Work out materials, quantities and fair prices before you call a contractor. Every tool shows its math, and you can type in your own prices.

✓No sign-up
✓Formulas shown
✓Printable lists

Live calculators

Calculators for every home service

52 services, 55 tools, all live. Every tool shows its formula and its sources.

Live

Home improvement formula cheat sheet

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What you need
Formula
Result in
Concrete volume
L × W × (depth in ÷ 12) ÷ 27
cubic yards
Concrete bags
cubic feet ÷ 0.6 (80 lb bag)
bags
Fence posts
ceil(run ÷ spacing) + 1 + corners + gates
posts
Pavers
area × (1 + waste) ÷ paver face area
pieces
Gravel base
area × (depth in ÷ 12) ÷ 27 × 1.15
cubic yards
Epoxy coverage
1,604 ÷ wet mils
sq ft per gallon
Paint coverage
wall area ÷ 350–400 sq ft per gallon
gallons
Roofing squares
roof area ÷ 100
squares
Foundation piers
ceil(wall ft ÷ spacing) + 1
piers

Add a 5 to 15 percent waste allowance to material quantities. Every row above links to a live calculator.

How to measure for any home project

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1
Use feet for length and widthInches for depth or thickness. Convert before you type: 6 in = 0.5 ft.
2
Split odd shapesBreak L-shapes and curves into rectangles and triangles, calculate each, then add.
3
Measure at several pointsGround and walls are rarely even. Use the deepest or longest measurement.
4
Add waste, then round upBuy whole bags, boxes and gallons. Running short mid-job costs more than leftovers.
Photo by Ivan Henao on Unsplash

Home improvement calculator FAQ

What is the best free home improvement calculator?

The best one is the calculator built for your exact job. A concrete calculator counts cubic yards and bags, a fence calculator counts posts and pickets, and a cost estimator prices labor and materials together. All LocalServiceHQ calculators are free, need no sign-up and show their formulas.

Quantities use standard trade formulas, the same volume, coverage and spacing rules contractors use, so they are accurate when your measurements are. Prices are typical US ranges; local labor, access and season change real quotes, so type in your own prices for the closest number.

Yes. Each tool adds a waste allowance, usually 5–15%, that you can change. Waste covers cuts, spills, uneven ground and breakage.

Yes. The cost estimators break a job into line items. Type the contractor's numbers into each line to see where the quote sits against the typical range.

Defaults are national US ranges. City cost guides show local prices where we have checked them, and you can edit any price in any tool.

Measure length and width in feet and depth or thickness in inches. Split odd shapes into rectangles, calculate each one and add them together. Measure twice before you order.

The concrete calculator has a free embed code at the bottom of its page; more tools are getting one. Keep the credit link in place.

Roofing, painting, HVAC sizing, flooring, solar and more. The full list is in the "Calculators for every home service" section above; new tools go live one by one.

How our calculators work

Formulas follow manufacturer data sheets and common trade practice. Each tool shows its formulas and the date the page was last updated. Spot an error? Tell us and we'll correct it.

1
Standard trade formulas
Volume, coverage and spacing rules that contractors and manufacturers use, shown on every result.
2
Waste built in
Each tool adds a waste allowance you can change, so you don't run short mid-job.
3
Your prices, not ours
Default prices are typical US ranges. Type in your store's or contractor's price on any line.
4
Estimates, not quotes
Local labor, access and soil change real prices. Use the result to compare quotes, not replace them.
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