Paint Calculator: How Much Paint for a Room or HDB Flat
Room size
Measure along the floor. Ceiling height 2.6 m is a typical assumption for HDB flats; measure yours.
1.89 m² each (0.9 × 2.1 m)
Width × height of the opening.
Paint
Assumption: 10 m²/L, a common rule of thumb for smooth walls. Use the coverage printed on your tin; rough or porous walls get less.
- Walls30.4 m² × 2 coats ÷ 10.0 m²/L · buy 1 × 5 L + 2 × 1 L6.1 L
- Ceiling10.5 m² × 2 coats · buy 1 × 2.5 L2.1 L
Wall paint to buy
1 × 5 L + 2 × 1 L
- Wall area to paint
- 30.4 m²
- Ceiling paint
- 2.1 L (1 × 2.5 L)
- Total tins
- 4
How this works
For one room, wall area = 2 × (length + width) × ceiling height, minus 1.89 m² per door (0.9 × 2.1 m) and the window area you enter. Paint needed = area × coats ÷ coverage per litre, using an assumed 10 m² per litre per coat, a common rule of thumb for smooth walls (use the coverage printed on your tin).
For a whole HDB flat, floor areas are the internal floor areas of new BTO flats in HDB's June 2024 launch: 46 m² (2-room Flexi), 66 m² (3-room), 90 m² (4-room), 110 m² (5-room) and 115 m² (3Gen). As kitchens and bathrooms are usually tiled, the painted wall area is assumed to be about 1.7 times the floor area after openings, and the ceiling about 0.75 times. These are rough assumptions; measure for a precise quote.
Tins are picked from 5 L, 2.5 L and 1 L sizes to cover the litres with little leftover and few tins. Ceiling paint and any sealer or primer coat are counted separately.
FAQs
How much paint do I need for a bedroom?
About 6.1 litres for two coats on a 3.5 × 3 m room with a 2.6 m ceiling, one door and one 1.5 m² window (30.4 m² of wall at 10 m² per litre). That is one 5 L tin and two 1 L tins, plus 2.1 litres if you paint the ceiling.
How much paint do I need for a 4-room HDB flat?
Roughly 31 litres of wall paint for two coats on a 90 m² 4-room flat (about 153 m² of painted wall), and about 13.5 litres for the ceilings, assuming 10 m² per litre per coat.
How many square metres does 1 litre of paint cover?
About 10 m² per litre per coat on smooth walls is a common rule of thumb, so 5 litres covers about 50 m² for one coat or 25 m² for two. The exact figure is printed on the tin, and rough, porous or new plaster walls take more.
How many coats of paint do I need?
Two coats for most repaints. A big colour change or a dark-to-light change may need a third coat or a primer first.