How Much Paint Do I Need for a Room in the UK? (2026 Guide)

That said, coverage varies meaningfully by product, paint brand, and the condition of your walls — so treat that figure as a starting point. The most reliable approach is to measure your room accurately and use our free UK paint calculator to get a personalised estimate in under a minute.

Equally, running short and needing to make an emergency trip mid-job risks colour inconsistency if batch numbers differ between tins — a genuine decorating headache. Getting the quantity right at the start is both a money-saving and a quality decision.

To calculate your paintable wall area, measure each wall (height × width) and add them together. Then subtract the area of any doors (roughly 1.8 m² each for a standard door) and windows (a typical double-glazed window is around 1.2–1.5 m²). For example, a bedroom with four walls each 2.5 m high — two walls 3.5 m wide and two 4 m wide — gives a total wall area of 37.5 m², less one door (−1.8 m²) and one window (−1.4 m²), leaving a net paintable area of approximately 34.3 m².

Using a mid-range coverage rate of 11 m² per litre, that works out to 3.1 litres per coat, or 6.2 litres for two coats. In practice, you would buy 2 × 2.5-litre tins plus a small 1-litre tin, or a 5-litre tin and a 2.5-litre tin. Always check the coverage rate printed on the tin before you buy — premium paints and specialist finishes often cover less per litre than standard emulsion. Matt, silk, and eggshell finishes also behave differently.

If you're painting the ceiling too, measure it separately (length × width of the room). A 3.5 m × 4.0 m bedroom ceiling is 14 m², which at 10–12 m²/litre adds roughly 2.5–3 litres for two coats of ceiling white.

Results are estimates only — always check the coverage rate on your paint tin and consult your chosen retailer.

• Small single bedroom (7–9 m² floor area): approximately 5–7 litres for two coats
• Double bedroom (11–14 m² floor area): approximately 7–9 litres for two coats
• Living room (16–22 m² floor area): approximately 9–11 litres for two coats
• Kitchen/diner (12–18 m² floor area): approximately 7–10 litres for two coats
• Bathroom (4–7 m² floor area): approximately 4–5 litres for two coats
• Hallway (straight): approximately 5–7 litres for two coats

You may need a third coat if you're painting a light colour over a dark one, the surface is bare or newly plastered (in which case a diluted first coat or purpose-made mist coat is often recommended to seal the surface — check your paint tin's instructions), or the previous finish was very uneven. If you're unsure whether a primer or mist coat is needed, the coverage and preparation instructions on your paint tin or the manufacturer's website are the most reliable guide. Getting this right upfront means buying the correct total quantity before you start.

The calculator also works for multiple rooms if you're redecorating across the house, making it easier to plan a single trip to the shop rather than returning for extra tins. For other home project planning, our home tools hub includes calculators for wallpaper, flooring, and tiles — useful if you're doing a full room makeover.

Don't automatically buy extra just in case. It is usually better to hold on to your receipt and check the retailer's returns policy — unopened tins can often be returned. Buying one tin less than you think you need and returning for one more is less wasteful than buying two extra you never open. Keep a note of the paint reference too: if you need to do touch-ups in future, note the colour code and brand — most retailers can rematch by code even years later.

• Measure twice — the most common cause of buying wrong is a measurement error; use a metal tape measure rather than a soft one
• Check batch numbers — if buying more than one tin of the same colour, make sure the batch numbers match to avoid slight colour variation on large surfaces
• Buy in the right tin size — a 5-litre tin is typically better value per litre than two 2.5-litre tins; work out your total quantity first, then choose the most economical combination

Q: What is paint coverage per litre in the UK? A: Standard interior emulsion paint typically covers approximately 10–12 m² per litre per coat. This figure is published on the tin by the manufacturer, and it varies between brands, paint types (matt, silk, eggshell), and the condition of the surface. Always check the coverage stated on your specific tin before calculating how much to buy.

Q: Do I need 1 or 2 coats of paint? A: Two coats is the standard recommendation for most interior painting jobs. One coat may suffice if you are painting a similar colour over an existing finish in good condition, but for a full redecoration, a colour change, or fresh plaster, two coats will give a more even and durable result. Some surfaces may need a primer or mist coat first.

Q: How do I calculate how much paint I need for a wall? A: Measure the height and width of each wall in metres, multiply to get the area in m², subtract the area of any doors and windows, then divide by the coverage rate on your paint tin. Multiply the result by the number of coats you plan to apply. Or enter your measurements directly into our free paint calculator.

Q: How much does it cost to paint a room yourself in the UK? A: The cost depends on the size of the room, the brand of paint you choose, and what preparation materials you need. Paint prices vary significantly by retailer and product range — check current prices at your chosen retailer. Using the paint calculator first means you won't buy more than you need, which is one of the most straightforward ways to keep the cost down.