Can I use normal paint on radiators?

No, you should use specialist radiator paint that is heat-resistant (withstands temperatures up to 130°C). Normal emulsion or gloss will yellow, crack and peel when the radiator heats up. Radiator enamel, satin, or spray paint are formulated to remain stable under heat cycling.

Do I need to sand radiators before painting?

Yes, lightly sand the entire surface with 120-grit sandpaper to create a key for the new paint. If the existing paint is flaking, sand back to bare metal. Wipe clean with a damp cloth to remove dust, then apply a coat of radiator primer before painting. Always paint with the radiator OFF and cold.

How many coats of radiator paint do I need?

Two thin coats are standard for a good, durable finish. Apply the first coat and allow to dry fully (typically 4-6 hours) before applying the second. Thin coats dry faster and produce a better finish than one thick coat, which can drip and sag on the warm metal surface.

Why does a double panel radiator need much more paint?

A double panel (Type 22) radiator has approximately 2.5× the paintable surface of its flat front face. Behind the front panel there are convector fins, a gap, then the back panel. Column radiators have even more surface area — a 4-column radiator has roughly 5× the area of its flat front dimension.

Is spray paint better for radiators?

Spray paint gives a smoother, factory-like finish and is excellent for reaching between fins on double panel and column radiators. However, it requires good masking of the surrounding area. One 400ml can typically covers about 2 m². For large radiators or multiple units, brush-on paint may be more economical.

TradeCalcs

Radiator Paint Calculator — How Much Radiator Paint Do I Need?

Calculate specialist radiator paint for all radiator types. Accounts for fins, columns and hidden surfaces.

Number of Radiators

Radiator Type

Radiator Height

Common heights: 300, 450, 600, 700mm

Radiator Width

Width across the front

Paint Type

Number of Coats

2 coats recommended

Include wastage allowance

Adds 15% for drips and complex surfaces

Wastage Percentage

15% recommended for radiator work

Include radiator primer

Metal primer for bare or previously-painted radiators

Price Per Litre (optional)

How We Calculate This

Our radiator paint calculator accounts for the hidden surfaces that make radiators use far more paint than their flat dimensions suggest. Different radiator types have vastly different total surface areas.

The formula

Surface area = Front area × Surface multiplier × Coats
Paint needed = Surface area × Wastage factor ÷ Coverage rate

Surface area multipliers

Single panel (Type 11): 1.5× flat front area
Double panel (Type 22): 2.5× flat front area
2-column radiator: 3.0× flat front area
3-column radiator: 4.0× flat front area
4-column radiator: 5.0× flat front area
Towel rail: 2.0× flat front area

We recommend 15% wastage for radiator painting as the complex surfaces and vertical application result in more paint loss than flat wall painting.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.