Paint Coverage For Steel Calculator

Work out paint coverage for steel instantly with clear inputs, formula shown and shareable results.

About Paint Coverage For Steel Calculator

Structural steel paint quantities start from theoretical coverage, 1000 times volume solids divided by system dry film thickness in microns, then apply a loss factor. Losses of 25-40 percent are normal on open steelwork because of overspray past flanges and the extra film needed on rough blast profiles and edges.

Formulas

Theoretical coverage

m²/L = 1000 x volume solids / total DFT µm

Paint quantity

Litres = area / (theoretical coverage x (1 - loss factor))

Worked example

With the default values below, Paint Coverage For Steel Calculator returns Paint required of 96.15. Change any input above and every figure here is recalculated in your browser.

Inputs used

Steel surface areaminimum 0.1 m²: 350 m²
Total system dry film thicknessminimum 1 µm: 125 µm
Volume solidsaccepts 5–100 %: 65 %
Application loss allowanceaccepts 0–70 %: 30 %

Results

Paint required: 96.15 L
Theoretical coverage: 5.20 m²/L
Practical coverage: 3.64 m²/L
Consumption per square metre: 0.2747 L/m²

Step by step

1Values used
2Theoretical coverage
3Paint quantity
4Paint required= 96.15 L
5Theoretical coverage= 5.20 m²/L
6Practical coverage= 3.64 m²/L
7Consumption per square metre= 0.2747 L/m²

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Paint Coverage For Steel figure worked out?

m²/L = 1000 x volume solids / total DFT µm. Structural steel paint quantities start from theoretical coverage, 1000 times volume solids divided by system dry film thickness in microns, then apply a loss factor.

Why does lattice steelwork need more paint per square metre?

Small members have a high edge-to-area ratio, and edges hold less film so they are stripe-coated. Overspray losses are also far higher than on flat plate.

What values do I need to enter?

This calculator takes 4 inputs: Steel surface area, Total system dry film thickness, Volume solids, Application loss allowance. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.