Skip to content
Interior Redesign AI
Free · no sign-up · runs in your browser

Free paint and wall calculators

4 free calculators for paint and wall coverings: how much paint for trim, doors and ceilings, how many rolls of wallpaper, and what painting a room costs DIY or with a painter. Coverage figures come from the paint makers' own spec sheets.

Updated · By the Interior Redesign AI editorial team · Sources cited on the page

The same bedroom with every wall painted a deep red; the door, trim and ceiling stay white

How much to buy

Paint and wallpaper quantities from the makers' coverage figures.

Trim Paint CalculatorQuarts and gallons for baseboards, casing, crown and doors, from linear feet.Free, no sign-upCeiling Paint CalculatorGallons for a ceiling, with the spread rate cut for texture or popcorn.Free, no sign-upWallpaper CalculatorRolls by strips per roll, with pattern repeat and half-drop waste.Free, no sign-up

Cost

What the job costs, DIY or with a painter.

Interior Painting Cost CalculatorPro vs DIY cost to paint a room, walls only or the full room.Free, no sign-up

How we calculate

Each tool does plain, visible arithmetic in your browser, with no AI and no server call, and shows its formula, a worked example and its sources on the page. Code figures cite the model code section, quantities cite the manufacturer's published spec, and prices cite a named cost guide with the date we checked it.

Where we had to assume something, the page says so and the widget lets you change it. Results are planning numbers, not quotes or code rulings.

More tools for this project

Then see it on your room

The same photo, before and after an AI render. Your walls, windows and layout stay; the finishes change.

An empty bedroom with white walls, a white door, a ceiling fan and a large window
Before
The same bedroom with every wall painted a deep red; the door, trim and ceiling stay white
After: Deep red (AI illustration)

Questions

Are these paint tools free?

Yes. They run in your browser, cost nothing and need no account. Only the AI paint preview on your own photo needs a free account.

Where do the coverage numbers come from?

From the paint makers' published product data sheets (spread rates per gallon) and wallpaper makers' roll sizes. Each page names the products and links the sheets.

Are the cost results quotes?

No. They are planning ranges from national cost guides. Get local quotes before you hire.