How to Use the Steel Surface Area for Painting Calculator
Before ordering paint for a steel structure, you first need an accurate painting surface area. This calculator multiplies the section's perimeter by member length and quantity to get total surface area, then combines it with the number of coats and coverage rate to show the paint volume needed right away.
Enter the perimeter from the shape's size table (AISC W-shapes, angles, pipe, etc.). If a table does not list perimeter directly, adding up the outer edge lengths gives a close enough approximation. The area formula is perimeter (ft) x length (ft) x quantity, so as long as the units are consistent the result will be accurate.
Coverage rate varies by product, so use the spread rate listed on the paint manufacturer's technical data sheet (TDS) for the most accurate result. It is common practice to order 5-10% more than the calculated volume to account for material loss during application.
Frequently Asked Questions
Use the perimeter listed in the steel shape's size table (or add up the outer edge lengths yourself). Check the AISC shapes database or your supplier's spec sheet for exact values.
Surface area alone doesn't tell you how much paint to order, so entering the number of coats and the coverage rate lets you see the total paint volume needed right away.