What it calculates
Estimate trim paint from linear feet and coverage.
Trim Paint Calculator
Estimate trim paint from linear feet, average width, coats and coverage.
Planning and estimating aid only. Verify project requirements, manufacturer instructions, adopted codes, permits, and field conditions before performing regulated work.
Painting estimating
How to Use This Calculator
Use the field units shown below, then compare your result with the worked example. Do not enter a 4-inch face as 4 feet.
How the calculation works
Linear feet of trim × average painted width gives surface area; coats are applied before dividing by coverage.
What the result means
Complex profiles can have more paintable surface than their face width suggests.
Convert trim length into a simple painted area
For 120 linear feet of trim with a painted face width of 4 inches, one-coat area is 120 × (4 ÷ 12) = 40 square feet. Two coats give 80 square feet. At 400 square feet per gallon, the theoretical need is 0.2 gallons.
Contractor tip: Do not enter a 4-inch face as 4 feet. Compare the theoretical quantity with product packaging and application losses, especially on small jobs where a minimum purchase dominates.
Verify the final quantity
The width input represents the total painted surface width you choose to include. Detailed profiles, edges, returns and multiple faces may need a larger measured width. This tool does not add a waste allowance.
Good practice: Compare the calculated quantity with plans, specifications, product packaging and current field conditions before purchasing material.