Paint, Flooring & Wallpaper Calculator
Estimate the amount to purchase for a paint, flooring or wallpaper project. Use product-label coverage and include a waste allowance.
How to use this tool
- Choose paint, flooring or wallpaper. Select metric or US customary units. Switching units converts the entered measurements.
- Enter the measured surface dimensions and the actual product coverage or package size.
- Add a waste allowance, calculate and check the rounded package count against the product label.
Worked example
For 100 sq ft of paint area, two coats, 400 sq ft coverage per US gallon and 10% waste, the estimate is 0.55 US gal. With one-gallon cans, that rounds up to one can.
Calculation and generation rules
Paint quantity = area × coats × (1 + waste rate) ÷ coverage. Flooring uses room area plus waste. Wallpaper uses wall area minus openings, plus waste, divided by roll area. US customary uses the international foot (0.3048 m) and US liquid gallon (3.785411784 L).
Frequently asked questions
Is the wallpaper result an exact roll count?
No. This is an area estimate. Pattern repeats, strip lengths, offcuts and matching are not modeled. Plan the actual strip layout before buying.
Are US and Imperial gallons the same?
No. This tool uses US liquid gallons, never Imperial gallons. Match the unit stated on your product.
Which coverage value should I enter?
Use the product manufacturer’s coverage for one coat or one package. Surface texture and application can change actual consumption.
About this tool
UsefulSet builds small browser-based tools. AI assists with development and explanations; automated tests check generation rules and edge cases. This is an independent tool and is not an official service of Google, OpenAI or Anthropic.
Contact and corrections
Report an issue to [email protected]. Include reproduction steps and the expected result, but remove personal or confidential information.
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Terms of use
This free tool provides a draft and explanatory guidance. You are responsible for verifying the output, accuracy of your inputs, applicable requirements and the effect on your website. Availability, search rankings, crawler compliance and revenue are not guaranteed. Do not enter confidential customer data. Use generated output only after reviewing it against the relevant official specifications.