MeasureTwice

Trim paint calculator

Trim paint calculator for baseboards, doors, windows, and crown.

Estimate quarts of trim paint from room perimeter, casing counts, trim width, coats, and coverage before buying paint, brushes, tape, caulk, and prep supplies.

Trim paint estimate

Trim paint calculator

Live estimate

Quick trim paint answers

Common trim checks

12 x 12 bedroom trim

1 qt

90 linear ft

0.58 qt calculated

20 x 15 living room trim

1 qt

140 linear ft

0.90 qt calculated

12 x 12 room with crown

1 qt

138 linear ft

0.97 qt calculated

Shopping list

Compare trim paint and prep supplies

Primary material

1 qt cans

Door and trim paint

Use the quart count as your buying starting point, then verify sheen, tint base, and label coverage before checkout.

Large trim jobs

1-gal trim paint

For whole-house baseboards, doors, or crown, compare the quart count against gallon pricing and tint consistency.

Application tools

Angled brush, tape, and mini roller

Trim work is slow without a good angled sash brush, painter tape, small roller, tray, and drop cloth.

Prep and finish

Caulk, spackle, and sanding sponge

Caulk trim gaps, fill nail holes, sand rough edges, and clean dust before the finish coat.

Formula shown

How trim paint estimates work

Linear feet

baseboards = perimeter - doors x 3 ft; casing = doors x 17 ft + windows x 14 ft

Paintable area

trim area = linear feet x trim width in / 12

Quarts to buy

quarts = area x coats x allowance / coverage per quart

Sources

Reviewed for estimating accuracy

Written by

MeasureTwice Editorial

DIY estimating and home-improvement research

Reviewed by

Maya Collins

Interior repaint takeoffs, prep planning, and room paint quantities

Last updated: June 21, 2026

Estimate only. This calculator is not a quote. Verify product yield, price, delivery minimums, and local conditions with your supplier or contractor before buying materials.

Baseboards

45 ft

Room perimeter adjusted for doors.

Door/window casing

45 ft

Planning linear feet around openings.

Crown molding

0 ft

Only included when crown molding is on.

Related paint tools

Painting rooms or exterior siding?

Walls, siding, and trim each use different area logic, so use the focused calculator for that part of the job.

FAQ

Trim paint calculator questions

Quick answers for trim paint quarts, baseboards, casing, crown molding, coverage, and finish choice.

How much trim paint do I need? +

Measure or estimate the linear feet of baseboards, door casing, window casing, and crown molding. This calculator converts linear feet and trim width into square feet, then applies coats and coverage per quart.

How many square feet does a quart of trim paint cover? +

Many quart-size trim paints list about 100 square feet of coverage, but the label, surface texture, color change, and brush technique can change the actual amount.

Why does the calculator use linear feet? +

Trim is narrow and long, so linear feet are usually easier to estimate than wall-style square footage. The calculator multiplies linear feet by trim width to get paintable area.

Should I include doors and windows? +

Include casing if you plan to paint the trim around doors and windows. The calculator uses planning linear feet per opening, but you can adjust counts to match the room.

Do I need special trim paint? +

Trim usually gets satin, semi-gloss, or gloss paint because it needs to handle scuffs, cleaning, and hand contact better than flat wall paint.