Paint Calculator
Planning a decorating project? Our calculator helps you determine how much paint you'll need to buy, saving you from multiple trips to the shop or wasting money on excess.
Room Details
Results
You will need to purchase:
3
x 2.5L tins
OR
2
x 5L tins
Understanding Your Paint Needs
Surface Area is Key
The foundation of any paint calculation is the surface area. Our calculator starts by working out the total area of your walls (2 x (length + width) x height). We then subtract the areas for standard doors and windows, as these don't need painting. This gives you the 'paintable area', which is the crucial figure for determining how much paint to buy.
The Importance of Coats
A single coat of paint is rarely enough for a professional finish. We recommend a minimum of two coats. The first coat acts as a base, and the second ensures even coverage and true colour depth. If you're making a dramatic colour change (like painting white over a dark wall), you might even need a third coat.
Coverage and Paint Type
Paint coverage, measured in square metres per litre (m²/L), varies between brands and finishes (e.g., matt, silk, gloss). A typical value is around 12 m²/L, but porous surfaces like new plaster will absorb more paint, reducing coverage. Always check the manufacturer's recommendation on the tin. Our calculator uses a default of 12, but you can adjust it for better accuracy.
Related Calculations
Decorating involves more than just paint. If you're considering wallpaper, our Wallpaper Calculator can help you figure out how many rolls you need. For other area-based projects, from flooring to garden turf, the Square Footage Calculator is an indispensable tool.
Frequently Asked Questions
Related Calculators
Percentage Calculator
Calculate percentages quickly: find a percentage of a number, percentage change,...
Loan Repayment Calculator
Calculate monthly repayments and total interest on personal loans.
Household Budget Calculator
Plan your monthly household budget and see where your money goes.
Debt Repayment Calculator
Plan your debt repayment strategy using the snowball or avalanche method.
Tip Calculator
Calculate tip amounts and split bills between diners at UK restaurants.
Gift Split Calculator
Split the cost of a group gift fairly between contributors.