Paint Calculator
🇮🇳 India version
Indian rooms are measured in feet and paint is sold in litres, and the spread rate on the bucket is usually in square feet per litre. This version starts in feet and litres, uses a typical 10 square metres per litre, and adds primer as a separate line so a fresh wall is not under-bought.
Use Paint Calculator online
Paint Calculator
Work out how much paint a job really needs — walls, ceilings and trim, adjusted for texture, colour change and the number of coats — then turn it into a shopping list.
Area to cover, by room
India rules and figures
- Indian rooms are usually described in feet and paint coverage on buckets in square feet per litre, so this page starts in feet and litres.
- India’s starting wall coverage is 10 m² per litre, lower than the 12 used for other countries; it is a typical manufacturer figure and not an official value.
- India’s standard GST rate is 18% for most goods, so enter the bucket price as billed.
- Buckets start at 2.5 litres, and prices are entered in rupees with no default amount.
Sources: Income Tax Department: India tax authority (checked 2026-11-08)
How the Paint Calculator works
The wall area is the perimeter times the height, less a standard door and window for each count. The ceiling is the floor area. Each product’s area, coats and effective spread rate give litres, rounded up to whole buckets.
litres = (sq ft × coats) ÷ (sq ft per litre ÷ texture ÷ colour); primer area = walls + ceiling + trim
- The starting wall rate is 10 m² per litre, shown as 108 sq ft per litre, and woodwork and primer use 92 sq ft per litre. These are typical figures, lower than elsewhere, and not official.
- Primer is off until you switch it on. It then covers wall, ceiling and woodwork area for one coat.
- Rough or porous surfaces raise use: 1.25 for heavy texture, 1.4 for bare plaster and 1.6 for brick or render, common in new construction.
- Buckets start at 2.5 litres and the price stays blank, so type the cost of one including GST.
How to use the Paint Calculator
- Add the room sizes. Enter length, width and height in feet and the numbers of doors and windows for each room, then Add room for more.
- Choose what to paint. Untick the ceiling or woodwork for rooms where only the walls are being redone.
- Match the wall condition. Under Paint needed choose a surface such as bare plaster or brick, which absorb far more paint than a painted wall.
- Turn primer on. Switch Include primer on for new walls and set the bucket size and price in rupees.
- Share the quantities. Copy list gives you a text order for the painter or shop, and Export CSV a sheet.
Example: A 14 × 12 × 10 ft room with primer, in litres
The room has 2 doors and 2 windows, so 460.38 sq ft of net wall and 168 sq ft of ceiling. Primer covers 628.38 sq ft at one coat and needs 6.83 litres (3 buckets of 2.5 litres). Two coats of wall paint come to 10.02 litres, or 5 buckets, because 108 sq ft per litre falls to 91.91 with the colour uplift. The ceiling takes 3.11 litres, which is 2 buckets.
When to use the Paint Calculator
- Painting before Diwali. Add the living room and bedrooms, tick walls and ceiling, and see how many buckets to book with the painter.
- New construction walls. Choose bare plaster, switch on primer and read the extra litres a fresh wall absorbs.
- Rented flat repaint. Tick only the walls and see the litres needed for a single colour touch-up before handing back keys.
- Comparing bucket sizes. Change the container to 1, 4 or 10 litres to see which pack leaves the least spare paint.
What the Paint Calculator does not do
- The starting spread rates are typical manufacturer figures, not an official standard, so a tin that states a different rate needs that figure typed into the spread-rate box. Other countries start with litres and no price, which you enter.
- Doors and windows use one standard size each, so a patio door or a large picture window is under- or over-deducted.
- Rooms are rectangles with flat ceilings and no alcoves, stairs, gables or radiators.
- The texture and colour factors are rules of thumb, not a paint maker's data. Check the spread rate printed on your tin.
- Nothing is saved: the rooms reset to the two examples when you reload.
When something else is a better fit
- When you want floor area, perimeter and a boxes-of-material order for flooring, use the Room Measurement Calculator.
- When you need to convert gallons, litres or square measures, use the Unit Converter.
- When the surface is exterior brick, a ceiling with beams or a spray job, use the paint manufacturer's own calculator or a trade quote.
Questions about the Paint Calculator
How much paint does a 14 by 12 foot room need?
With a 10 ft ceiling, 2 doors and 2 windows, walls need 10.02 litres for two coats and the ceiling 3.11 litres. Primer adds 6.83 litres. Real use varies with the surface and the brand.
Why does the page use 10 m² per litre?
It is a typical manufacturer figure for Indian wall paints, set lower than the 12 used elsewhere. No official standard exists, so replace it with the coverage in square feet per litre on your bucket.
Is primer included automatically?
No. Include primer is off until you switch it on. It then adds one coat across wall, ceiling and woodwork area, using a lower spread rate than top coat paint.
What if my walls are rough?
Choose the heavy texture, bare plaster or brick setting under Surface being painted. They multiply the paint absorbed by 1.25, 1.4 or 1.6, which can add several buckets to a large room.
How are buckets rounded?
Each product rounds up to whole buckets of the size you enter. If the wall needs 9.6 litres in 2.5 litre buckets, that is 4 buckets, so some paint is spare for touch-ups.