Paint / coating area estimator

What this calculator does

For a coating quote you need square feet, not tons. Enter the total steel weight and pick a section class — light, medium or heavy — and the page estimates surface area from a square-feet-per-ton factor, then gallons per coat from your coverage rate. The class factors are planning assumptions; the applicator's numbers govern.

Worked example

20,000 lb (10 tons) of medium sections at 200 ft²/ton = 2,000 ft². At 250 ft² per gallon per coat, that is 8.0 gallons a coat; two coats, 16 gallons plus loss.

Common questions

Which class is my job?

Light (~300 ft²/ton) is mostly small angles, channels and light beams — lots of surface per pound. Heavy (~120 ft²/ton) is big columns and thick plate. Most building jobs sit in the middle.

Does it account for spray loss or overlap?

No. The gallons are theoretical at the coverage you enter; add the applicator's loss factor on top.

Is this good enough for a bid?

For a rough number, yes. For a firm quote, a section-by-section area takeoff or the applicator's own estimate replaces it.