Steel paint area calculator

Surface area in m² and m²/t for coating quantities, free

Choose section or plate, then pick the section and its length or enter the plate sizes, to get the paint area in m² for one piece and in total, with the m² per tonne. Add every item of the job to the list for the total coating area.

1. What do you want to weigh?

2. Enter the sizes

Enter the sizes

ⓘ Steel density used: 7,850 kg/m³ (standard carbon steel)

Item	Qty	Weight (kg)	Paint (m²)

Settings

Density (kg/m³)

📄 Have the list in Excel or PDF? Upload it and get the weight →The same calculator inside Steel Optimizer: upload the file as it is, then press Calculate weight. Free.

📱 Add it to your phone's home screen: on iPhone, Share → Add to Home Screen; on Android, ⋮ → Add to Home screen. Your list stays saved on your device.

How the paint area is worked out

I, H and channel sections: the outside perimeter with square corners, which is on the safe side (typically a few per cent above catalogue surface areas).
Hollow sections (SHS, RHS, CHS): the outside surface only, because the inside is closed.
Angles: both faces of each leg: 2 × (A + B) per metre.
Plates: both faces plus the edges: 2 × L × W + 2 × t × (L + W).

m²/t = paint area (m²) ÷ weight (t)

For the paint quantity, litres ≈ area (m²) × number of coats ÷ spreading rate (m²/L) from the paint's data sheet, plus the loss allowance your painter uses.

Painting what you are about to cut? Steel Optimizer gives the paint area of the whole cutting list together with the cutting plan.

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