Paint Coverage Estimator

Planning to paint a room or an entire house? Use this Paint Coverage Estimator to work out how much paint you may need before buying it. Enter your wall dimensions, adjust the coverage rate and number of coats, and get an estimate of the paint quantity and cost. You can also account for doors, windows and extra paint for touch-ups to make your estimate more practical.

Currency & Measurement Units

Currency / Country

Choose a currency, then enter the price of paint in your local market.

Measurement Unit

This unit applies to wall length, height, and doors/windows dimensions.

Wall Dimensions

Total Wall Length

Add the lengths of all walls you plan to paint.

Wall Height

Doors to Exclude

Each door is estimated at 1.9 m² (20.5 ft²).

Windows to Exclude

Each window is estimated at 1.5 m² (16.1 ft²).

Other Openings Area (m²)

Optional: total area of large openings or sections not being painted.

This estimator assumes the walls are roughly rectangular. For separate rooms, add their wall lengths together if they share the same height.

Paint Coverage & Coats

Paint Coverage per Litre (m²/L)

Check the paint tin. A common planning range is about 8–12 m² per litre per coat.

Number of Coats

Extra Paint / Wastage (%)

Allows for touch-ups, spills and surface absorption.

Paint Can Size (litres)

Used to estimate the number of whole cans to buy.

Paint Price

Price per Litre ($)

The default price is an example only, not a live store price. Paint quality, finish and brand can change the cost.

Your Paint Estimate

Paint to Buy —

Gross Wall Area —

Area Excluded —

Net Paintable Area —

Total Area for All Coats —

Paint Needed Before Wastage —

Paint Including Wastage —

Can Size —

Whole Cans to Buy —

Estimated Paint Cost —

This estimate is for wall surfaces only and assumes the selected coverage rate applies to each coat. Actual paint use varies with surface texture, porosity, application method, colour changes and product instructions. Doors and windows use standard approximate areas; measure them for a closer estimate. Ceiling, primer, tools, labour, delivery and taxes are not included.

How to Use the Paint Coverage Estimator

Enter wall dimensions: Add the total length of the walls and their height.
Exclude openings: Enter the number of doors and windows, plus any additional area that will not be painted.
Set paint coverage: Check the paint manufacturer’s label and enter its coverage in square metres per litre.
Choose the coats and can size: Select how many coats you plan to apply and the size of the paint cans available.
Enter the paint price: Choose your currency and enter the local price per litre.

The estimator calculates the paint required, adds your selected wastage allowance, rounds up to whole cans, and estimates the total paint cost.

Paint Coverage Example

Suppose your walls have a combined length of 40 metres and a height of 2.7 metres. After excluding doors and windows, you have 102 m² of paintable wall area.

For two coats, paint coverage of 10 m² per litre, and 10% extra paint:

Net paintable area: 102 m²
Area for two coats: 204 m²
Paint needed before wastage: 20.4 litres
Paint needed after wastage: 22.44 litres
With 5-litre cans: 5 cans, or 25 litres

The final quantity may vary depending on the paint, wall surface and application method.

Frequently Asked Questions

How much paint do I need for a room?

It depends on the wall area, paint coverage and number of coats. Measure the walls, subtract doors and windows, and enter the details in the estimator.

How many coats of paint should I apply?

Two coats are commonly used for many interior painting jobs, but the right number depends on the paint product, wall condition and colour change. Follow the manufacturer’s instructions.

Does this estimator include ceilings?

No. It estimates wall paint only. Measure the ceiling separately if you want to estimate the paint needed for it.

Why should I allow extra paint?

An allowance can help cover spills, touch-ups, uneven surfaces and additional absorption. The amount needed depends on the condition of the walls and the painting method.

Disclaimer: This calculator provides an approximate estimate for planning purposes. Actual paint requirements and costs may vary. Check product coverage information and consult your paint supplier when necessary.