How Much Paint for Trim and Baseboards?
Trim is the one job where you measure in linear feet. Here is how to turn that into gallons.
A typical room needs about 1 quart of trim paint; a whole house needs 1 to 2 gallons. Trim is measured in linear feet, and the conversion is simple: multiply linear feet by the height of the trim in feet. 300 linear feet of 6-inch baseboard is 150 square feet.
Estimates only. Textured walls, high ceilings, sprayers and major colour changes can all increase the amount you need. Always buy slightly more than the calculation suggests.
Trim paint by linear footage
| Room / surface | Surface | Coats | Paint | Paint cost |
|---|---|---|---|---|
| One room, 100 linear ft of 6" trim | 50 sq ft | 2 | 1 gal | $42 |
| One room, 150 linear ft of 6" trim | 75 sq ft | 2 | 1 gal | $42 |
| Whole house, 300 linear ft of 6" trim | 150 sq ft | 2 | 1 gal | $42 |
| Whole house, 500 linear ft of 6" trim | 250 sq ft | 2 | 2 gal | $84 |
| Whole house, 400 linear ft of 3" trim | 100 sq ft | 2 | 1 gal | $42 |
| Whole house, 500 linear ft, one coat | 250 sq ft | 1 | 1 gal | $42 |
6-inch trim converted at 0.5 sq ft per linear foot. Two coats at 350 sq ft per gallon unless stated.
How to convert linear feet into paint
Trim is sold and measured by length, but paint is bought by area. The bridge between them is the height of the trim.
- Measure the total linear feet of trim you are painting — baseboards, door casings, window casings, crown moulding, chair rail.
- Multiply by the trim height in feet. A 6-inch baseboard is 0.5 feet. A 3-inch casing is 0.25 feet.
- That gives you square feet. Multiply by the number of coats and divide by the coverage on the can.
Worked example: a whole house with 300 linear feet of 6-inch baseboard is 300 × 0.5 = 150 square feet. Two coats is 300 square feet, which at 350 square feet per gallon is 0.86 — so 1 gallon.
Do not forget the trim you are not counting
The baseboard run is the obvious measurement and the one most people stop at. It is rarely more than half the total.
- Door casings: roughly 17 linear feet per door (two sides plus the head).
- Window casings: roughly 15 linear feet per window.
- Crown moulding: the same perimeter as the baseboard, so double the baseboard figure if you have it.
- Chair rail and picture rail: another full perimeter run each.
- Stair stringers, handrails and balusters: easily 60 to 100 linear feet on their own.
A house with 300 linear feet of baseboard often has another 250 linear feet of casings, crown and rails. That is why real trim jobs always need more paint than the baseboard measurement suggests.
Trim paint is a different product
Do not use wall paint on trim. Wall paint in a flat or matte finish will scuff, mark and wear through at the edges within a year — especially on door casings and baseboards, which take constant contact.
You want an enamel or waterborne alkyd in a semi-gloss or satin finish. Expect to pay more per gallon than wall paint: the calculator above uses $42, which is realistic for trim enamel.
One advantage: trim paint covers well and you often get away with one coat when refreshing a previously painted white trim in good condition. That halves the quantity.
Frequently asked questions
How much paint for baseboards?
Multiply the linear feet by the trim height in feet to get square feet. A whole house with 300 linear feet of 6-inch baseboard needs about 1 gallon for two coats.
How do I calculate trim paint in linear feet?
Convert to area first: linear feet times trim height in feet. A 6-inch baseboard is 0.5 ft tall, so 200 linear feet is 100 square feet.
Can I use wall paint on trim?
You can, but it will not last. Trim needs an enamel or waterborne alkyd in semi-gloss or satin, which forms a harder film that resists scuffing.
How much trim paint for one room?
Usually a quart or less. A typical room has 100 to 150 linear feet of trim, which is 50 to 75 square feet — well under half a gallon for two coats.