# Paint Calculator

> Estimate paint quantity from wall area, openings, coats, coverage, and waste allowance.

Page: https://askcalculators.com/calculator/paint-calculator/
Definition: https://askcalculators.com/calculator/paint-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/paint-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/paint-calculator/?roomLength=15&roomWidth=12&wallHeight=8&openingsArea=40&coats=2&coverage=350&wastePercent=10

## Inputs
- roomLength: Room length; type=number; required; default=15; min=0
- roomWidth: Room width; type=number; required; default=12; min=0
- wallHeight: Wall height; type=number; required; default=8; min=0
- openingsArea: Doors and windows area; type=number; required; default=40; min=0
- coats: Number of coats; type=number; required; default=2; min=1
- coverage: Coverage per gallon (ft²); type=number; required; default=350; min=0.000001
- wastePercent: Waste allowance; type=number; required; default=10; min=0; max=100

## Outputs
- gallons: Paint required (gallons); format=number; primary
- gallonsToBuy: Whole gallons to buy; format=integer
- paintArea: Coated area (ft²); format=number
- netWallArea: Net wall area (ft²); format=number

## Formula
paint = [perimeter × height − openings] × coats × (1 + waste%) ÷ coverage

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: This is a planning estimate. Product coverage and surface conditions can materially change actual paint use.