This is the ready-reference table we use internally. It lists realistic paint consumption per square metre for every common surface, so you can sanity-check a calculation or estimate by hand if you need to. All figures assume good preparation and proper application; porous or unprepared surfaces will use more.
Interior paint consumption
| Surface | Paint type | m² per litre (1st coat) | m² per litre (2nd coat) |
|---|---|---|---|
| New plaster (misted) | Matte emulsion | 9 | 12 |
| Painted drywall (sound) | Matte emulsion | 12 | 14 |
| Painted drywall (sound) | Eggshell / satin | 13 | 15 |
| Lining paper | Emulsion | 10 | 13 |
| Artex / textured ceiling | Matte emulsion | 7 | 9 |
| Wood trim (primed) | Gloss | 13 | 15 |
| MDF (primed) | Eggshell | 12 | 14 |
| Interior primer coat | Primer | 8 | 11 |
Exterior paint consumption
| Surface | Paint type | m² per litre (1st coat) | m² per litre (2nd coat) |
|---|---|---|---|
| Smooth render | Masonry paint | 7 | 9 |
| Rough cast render | Masonry paint | 5 | 6 |
| Pebble dash | Masonry paint | 4 | 5 |
| Brick (unpainted) | Masonry paint | 4 | 5 |
| Brick (previously painted) | Masonry paint | 6 | 8 |
| Concrete block | Masonry paint | 5 | 7 |
| Wood cladding | Exterior wood stain | 10 | 13 |
| Exterior primer | Stabilising solution | 8 | — |
Metal and special surfaces
| Surface | Paint type | m² per litre | Notes |
|---|---|---|---|
| Smooth metal (railings, gates) | Metal paint | 10–12 | Double for ornate work |
| Galvanised steel | Specialist primer + topcoat | 10 | Must use etch primer first |
| Radiator | Radiator paint | 12 | Single coat usually enough |
| uPVC | uPVC paint system | 12 | Needs adhesion primer |
How to use this table with the calculator
Find your surface and paint type in the tables above, note the first-coat coverage rate, then open the calculator, select "Custom coverage…" from the paint type dropdown and type that number into the Custom coverage field. The calculator now uses your exact rate rather than a default. For textured or porous surfaces, also nudge the Surface texture factor above 1.0 to reflect the extra real surface area.
Frequently asked questions
How much primer do I need per square metre?
Primer typically covers 8–10 m² per litre on porous surfaces and up to 14 m² on sealed ones. New plaster is very thirsty and may need two primer coats.
Does textured render use more paint?
Yes — a rough pebble-dash or stucco surface can consume 30–50% more paint than a flat wall of the same measured area because of the increased real surface area.
How much paint for metal railings?
Metal is hard to measure by area. As a rule of thumb allow 12–15 m² per litre for smooth metal and double that for ornate railings with lots of edges.
What about masonry and exterior brick?
Exterior masonry paint covers roughly 4–8 m² per litre because brick and render are highly porous. Always prime bare masonry with a stabilising solution first.