A 2 BHK can have very different wall area from another 2 BHK. The number of bedrooms tells you neither the wall height nor the size of the kitchen, passage and balcony. This worked example calculates three main rooms, then gives you a worksheet for the spaces that still need measuring.
Start with room measurements, not flat size
Measure length, width and wall height in feet for each rectangular room. The four-wall area is 2 × (length + width) × height. Subtract the area of each door and window that will not be painted. Measure a built-in wardrobe or tiled section separately if it covers part of a wall; do not assume its whole wall is paintable. If the room is L-shaped, divide it into wall sections and add those areas. The floor area advertised for a flat cannot tell you the paintable wall area.
| Room | Length × width × height | Doors and windows | Paintable walls |
|---|---|---|---|
| Living room | 12 × 10 × 9 ft | 40 sq ft | 356 sq ft |
| Bedroom 1 | 11 × 10 × 9 ft | 36 sq ft | 342 sq ft |
| Bedroom 2 | 10 × 10 × 9 ft | 36 sq ft | 324 sq ft |
| Three-room subtotal | Sample only | 112 sq ft | 1,022 sq ft |
For example, the living room is 2 × (12 + 10) × 9 − 40 = 356 sq ft. The same calculation gives 342 and 324 sq ft for the bedrooms. These figures exclude the ceiling, kitchen, bathroom, passage and any other area. Add those separately if they are in your painter's scope.
Convert wall area to litres and tins
Suppose you choose two coats and use an illustrative coverage of 100 sq ft per litre per coat. The three rooms need 1,022 × 2 = 2,044 sq ft of coverage. Divide by 100 to get 20.44 L; add a 10% planning allowance to get 22.484 L. Rounded up, the example is 23 L. If your chosen paint is sold in 20 L and 4 L tins, one of each buys 24 L, leaving a planned 1 L beyond the rounded estimate. Check actual packs and product coverage with the shop. A rough coverage range of 90–120 sq ft/L would move this three-room estimate, with the same two coats and allowance, to about 19–25 L after rounding. The real number depends on wall texture, product and application.
The paint calculator lets you add the three rooms, edit coverage and compare its litre range. Its recommended tin combination is a planning suggestion; exact stock and pack prices may make another purchase more sensible. Do not buy only from the bedroom count.
What about kitchen, bathroom and passage?
Walk the flat with a tape measure and record every space. A kitchen with cabinets and wall tiles may have little exposed paintable wall; a passage can have several long walls. In a bathroom, measure only the sections that will actually receive the product, above or beside tiles. Do not count a tiled section as an ordinary full wall. Ask about moisture, leaks, ventilation and a suitable finish before painting these spaces. The kitchen and bathroom planning guide covers those decisions.
| Space | Length × width × height (ft) | Openings or unpainted sections (sq ft) | Net painted wall area (sq ft) |
|---|---|---|---|
| Living room | __________ | __________ | __________ |
| Bedroom 1 | __________ | __________ | __________ |
| Bedroom 2 | __________ | __________ | __________ |
| Kitchen / utility | __________ | __________ | __________ |
| Bathrooms / passage / other | __________ | __________ | __________ |
Use a separate row for each room in the calculator. Its doors/windows field subtracts an area from the rectangular walls; if you use it to account for permanent tile or cabinetry as well, record that assumption in the brief so the painter understands the figure. For irregular or partly tiled rooms, the wall measurement guide shows how to total individual sections.
Turn the result into a useful quote
For a deliberately fictional example, 23 L at ₹350/L would be ₹8,050 of calculated paint at a per-litre rate. Actual tins can cost differently; 24 L purchased at that rate would be ₹8,400. A sample labour rate of ₹12 per sq ft on 1,022 sq ft is ₹12,264. Those figures exclude kitchen and bathroom work, primer, putty, repairs, ceiling, transport and taxes. They are not current market prices. Enter your supplier's pack price and your painter's written rate rather than using these example figures as a quote.
Ask whether labour is charged on gross or net area, whether doors and windows are deducted, who supplies materials, and what preparation is included. The painter quote checklist helps you compare like with like. Test the selected colour as a physical sample: a screen HEX value in the room colour preview is not a brand shade code.