Trim Paint Calculator — How Much Paint for Trim Do I Need?
Enter your linear feet of trim, width and number of coats to get the gallons of trim paint. No sign-up, no data stored.
Paint needed
How trim paint quantity is estimated
- Trim area (sq ft) = linear ft x width (in) / 12 (one visible side).
- Total area = area x coats.
- Gallons = ceil(total area / coverage per gallon).
- Extra suggests a quart when the math lands between sizes.
Baseboard with a toe detail and casing are both painted on the visible face, so one side is the right assumption. Crown molding adds a third side in some profiles - if you're painting behind the crown, bump the width field to the true visible dimension.
Trim run → paint reference
4-in average trim, 2 coats, 350 sq ft/gal.
| Linear ft | Area | Total (2 coats) | Gallons |
|---|---|---|---|
| 100 ft | 33 sq ft | 67 sq ft | 1 qt + |
| 250 ft | 83 sq ft | 167 sq ft | ~1 gal |
| 400 ft | 133 sq ft | 267 sq ft | 1 gal |
| 600 ft | 200 sq ft | 400 sq ft | 2 gal |
| 800 ft | 267 sq ft | 533 sq ft | 2 gal + |
Last updated: October 2026 · Coverage assumes smooth primed trim; bare wood and MDF drink more, so add primer at 250-300 sq ft/gal.
Trim paint FAQ
Spraying is faster and leaves a flawless finish, but requires masking everything nearby. Brushing with a good angle brush gives a hand-applied classic look and no masking. Many pros brush trim for control and spray only large flat surfaces.
Use a drywall knife as a shield held against the floor, or a purpose-made trim guard. Paint the baseboard first, let it dry, and cut the wall line with an angle brush - floors stay clean with a light wipe.
Trim after walls, unless you're spraying. Cut the wall edges first, then paint the trim so you can " "overlap the wall paint slightly without a visible seam. Caulk the gap between wall and trim before painting for a clean line.
Same as baseboard - semi-gloss or satin. Doors see heavy touch, so semi-gloss wins; windows take " "satin to reduce glare. Match the door casing and baseboard so the whole trim system reads as one color.
Water-based trim paints dry to touch in 1-2 hours and recoat in 3-4 hours; oil-based takes longer. " "Full cure takes weeks, so don't wash trim hard until then. One light sand between coats smooths brush marks.
Related calculators & guides
How Much Paint for Trim Do I Need?
Measuring trim runs, choosing sheen and cutting in around walls.
Read the guide →