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Paint Calculator

Enter wall size, coats, coverage and openings to estimate how much paint to buy, with a waste allowance for touch-ups and surface variation.

ft
ft
ft

Use a whole number.

sq ft/gal
%
Openings, container size and cost

Use 0 if there are no doors to subtract.

sq ft

Use 0 if there are no windows to subtract.

sq ft
gal

Set to 0 to skip container rounding.

$

Optional. No currency conversion is applied.

Result updated. Containers needed: 2 containers.

Result summary

Paint estimate

Main project estimate from the values entered.

Project estimate

2 containers

This is a planning estimate for paint quantity and container rounding.

Key numbers

Paint needed
1.89 gal
Containers
2 containers

Key takeaway

This estimate covers 301 sq ft over 2 coats and rounds up to 2 containers.

Project details

Paint details

Paintable area
301 sq ft
Paint needed
1.89 gal
Containers
2 containers
Estimated cost
$70
Gross wall area
352 sq ft
Openings subtracted
51 sq ft
Coated area with waste
662.2 sq ft

Save or share this result

Copy a plain-English summary or download a CSV with the inputs, results, warnings and general-estimate note.

Exports are generated in your browser. NoNoiseTools does not need to store your numbers or require an account.

How this paint calculator works

The calculator estimates wall area from room dimensions or uses the wall area you enter directly. It subtracts door and window areas, multiplies by the number of coats, adds the waste allowance, then divides by the coverage per gallon or litre.

Assumptions

Coverage varies by product, surface texture and colour change. Container and cost estimates are rounded from the values entered and are not brand recommendations or cost guarantees.

What this calculator does not include

This tool does not estimate trim, cabinetry, ceilings, labour, local pricing or decorating choices. It is a general material estimate only.

Key terms and assumptionsShort notes about paint coverage, openings, waste allowance and cost limits.
Coverage varies
Paint coverage changes by product, surface and colour change. The coverage field should come from the paint label where possible.
Openings
Door and window areas are subtracted from wall area when entered.
Waste allowance
Waste allowance adds a buffer for touch-ups, roller loss and surface variation.
No currency conversion
Cost formatting is for readability only. Unit or region settings do not convert currencies.

Guides and methodology

Plain-English notes that explain the assumptions behind related calculators and tools.

Related calculators

FAQs

How do I estimate how much paint I need?

Enter wall dimensions or wall area, number of coats, paint coverage and a waste allowance. The calculator subtracts doors and windows when those fields are included.

Should I include primer as a coat?

Include primer as a coat only if you want it counted in the paint estimate entered here.

Why does coverage vary by paint?

Paint coverage depends on the product, surface texture, colour change and application method. Check the label for the specific paint being used.

Can I use litres instead of gallons?

Yes. Choose metric units to use metres, square metres and litres. This changes labels and defaults only; it does not convert values already typed.

Does this include trim or ceilings?

No. This focused version estimates wall paint for a simple room or wall-area project.

Is the cost estimate guaranteed?

No. It is a rough material estimate from the price entered, not a quote or cost guarantee.