How many coats of paint do I need?

For most domestic projects, two coats of quality emulsion are standard. If you are painting a light colour over a very dark colour, you may require a third coat or a dedicated 'block-out' primer to achieve a perfect finish.

What is a 'Mist Coat'?

A mist coat is a mixture of roughly 70% emulsion paint and 30% water. It is applied to fresh, dry plaster to seal the surface. Without a mist coat, the plaster will suck the moisture out of standard paint too quickly, causing it to crack or peel.

How much paint does a 2.5L tin cover?

A standard 2.5L tin of emulsion covers approximately 30 square metres with a single coat. For a room requiring two coats, a 2.5L tin is usually sufficient for a small feature wall or a tiny bathroom.

Does the wall texture affect the amount of paint?

Yes. Heavily textured walls (like Artex or rough masonry) have a much larger surface area than smooth plaster. You should increase your paint estimate by at least 15-20% when painting textured surfaces.

How many coats of paint do I need?

For most domestic projects, two coats of quality emulsion are standard. If you are painting a light colour over a very dark colour, you may require a third coat or a dedicated 'block-out' primer to achieve a perfect finish.

What is a 'Mist Coat'?

A mist coat is a mixture of roughly 70% emulsion paint and 30% water. It is applied to fresh, dry plaster to seal the surface. Without a mist coat, the plaster will suck the moisture out of standard paint too quickly, causing it to crack or peel.

How much paint does a 2.5L tin cover?

A standard 2.5L tin of emulsion covers approximately 30 square metres with a single coat. For a room requiring two coats, a 2.5L tin is usually sufficient for a small feature wall or a tiny bathroom.

Does the wall texture affect the amount of paint?

Yes. Heavily textured walls (like Artex or rough masonry) have a much larger surface area than smooth plaster. You should increase your paint estimate by at least 15-20% when painting textured surfaces.

Paint Quantity Calculator

Estimate exactly how much paint to buy.

Total Wall Area (m²)

Deductions (m²)

Paint Type

Number of Coats

Paint Requirement

Decorating Tip: Porous surfaces like new plaster or bare wood will absorb much more paint on the first coat. We recommend applying a **Mist Coat** (diluted emulsion) to new plaster before your two main coats to prevent the paint from peeling.

Flawless Finishes: The Art of Calculation

Coverage Matters

Buying too much paint is a waste of money and creates storage headaches, but buying too little is even worse—mid-project batches can have slight colour variances.

Our **paint quantity calculator** helps you find the sweet spot, accounting for the different coverage rates of interior emulsions, exterior masonry, and high-gloss trim paints.

Standard Coverage Rates

Interior Emulsion12m² per Litre

Gloss / Satin14m² per Litre

Exterior Masonry10m² per Litre

Deductions & Windows

When measuring your room, calculate the total area of the walls (Perimeter x Height) and then subtract the areas of doors and windows. A standard UK internal door is roughly **1.6m²** to **2m²**, and a medium window is usually around **1m²**.

Don't forget the ceiling! If you are painting the ceiling the same colour as the walls, include its floor area in your total calculation.

The 'Batch' Rule

Always check the batch numbers on the bottom or side of the tins. If you need 10 litres (two 5L tins), make sure they have the same batch code to ensure the colour match is 100% identical.

Cutting In

'Cutting in' (painting the edges with a brush before rolling) uses more paint per square metre than rolling the main wall. Our calculator includes a small buffer for this detail work.

Pro Tip: Store Upside Down

Once you've finished, clean the rim of the tin thoroughly before hammering the lid shut. Store the tin upside down for a few seconds to create an airtight seal, then store it upright in a frost-free place. This prevents a 'skin' from forming on the paint.

Decorating & Painting FAQ

Project Disclaimer

Paint coverage is an estimate. High-quality trade paints often have better coverage than cheaper retail alternatives. Extremely dry or textured surfaces will significantly increase the volume of paint required.