Trim & baseboard paint calculator
Trim paint is measured in linear feet, not square feet. A typical room (12 × 14) has ~52 linear feet of baseboard plus ~30 lf of door and window casing. One quart of semi-gloss covers about 90 linear feet of trim with two coats — roughly one room's worth.
Estimates round up to the nearest quart and are based on Kompozit's published coverage. Buy slightly more for touch-ups and color changes.
How we estimate trim paint
- Baseboard: 4–5" tall = 0.4 sq ft per linear foot. 6"+ profile = 0.5 sq ft/lf.
- Crown molding: ~0.5 sq ft per linear foot (standard 3" crown).
- Door casing: ~12 linear feet per door (top + 2 sides), 0.4 sq ft/lf = ~5 sq ft per casing.
- Window casing: ~14 linear feet per window, ~5.5 sq ft each.
- Chair rail: ~0.25 sq ft per linear foot.
- Wainscot / board-and-batten: entered directly in sq ft.
A quart often does a whole room
For a typical 12 × 14 room with baseboard + casing on 1 door + 2 windows: ~52 lf baseboard + 12 lf door casing + 28 lf window casing = ~92 linear feet, or about 38 sq ft of paintable trim. At 425 sq ft/gal, two coats = 0.18 gallons — well under a quart.
Trim color: contrast or match?
Traditional spec: trim is white or off-white, walls are color. Modern alternative: trim matches the wall color in a slightly higher sheen — reads cleaner, feels architectural. The least good choice is a brilliant white trim against a warm wall — it looks accidental.
FAQ
Brush trim. A 2" angle sash brush handles baseboard, casing, and crown. Rolling trim creates stipple texture that doesn't belong on smooth millwork.
For baseboards, slide a thin metal trim shield against the floor and freehand the cut line. Painter's tape on flooring tends to lift the floor finish or trap paint underneath.
Yes — a fine bead of paintable acrylic caulk along every seam (top of baseboard against wall, casing-to-jamb, miters that opened up over time) is what separates pro-looking trim from DIY-looking trim. Caulk first, prime if needed, then paint.