Door Paint Calculator
Painting a single interior door uses about a quart of enamel. Painting every door in a 3-bedroom house (usually 10-14 doors) uses about 2 gallons. This door paint calculator tells you exactly how many gallons to buy and estimates the door paint cost so you do not overbuy expensive trim enamel (which runs $55-90 per gallon) or underbuy and run out mid-project.
How the Door Paint Calculator Works
Each standard interior door is 3 feet wide by 6 feet 8 inches tall, which is 20 square feet per side. A 6-panel or 2-panel door adds about 20% more paint surface because the recessed panels and stiles create profile area. Add both sides (40 sq ft) plus the 3 edges and jamb casing (about 6 sq ft), and you have roughly 46 sq ft per door.
Multiply by the number of doors and coats, divide by the coverage rate, and round up. The calculator does all of this for you.
Door Paint Cost Calculator
The door paint cost calculator side of the tool multiplies gallons rounded up by your paint price per gallon. 2025 door enamel pricing:
| Brand | Product | Retail / gallon |
|---|---|---|
| Benjamin Moore | Advance waterborne alkyd | $75-90 |
| Sherwin-Williams | ProClassic waterborne acrylic | $70-85 |
| PPG | Breakthrough! | $60-75 |
| Behr (Home Depot) | Alkyd Semi-Gloss Enamel | $50-65 |
| Valspar (Lowe's) | Signature Semi-Gloss | $45-60 |
Two coats on both sides of a standard interior door uses 0.11 gallons of paint, or about $7-10 of enamel at mid-tier pricing.
How Much Paint for a Standard Door
| Scope | Coats | Paint needed |
|---|---|---|
| 1 door, 1 side, 1 coat | 1 | 1/8 gal (1 quart) |
| 1 door, both sides, 2 coats | 2 | 1/4 gal (1 quart) |
| 6 doors, both sides, 2 coats | 2 | 3/4 to 1 gallon |
| 12 doors, both sides, 2 coats | 2 | 1.5 gallons |
| Whole 3-bed house (14 doors) | 2 | 2 gallons |
Interior vs Exterior Door Paint
Exterior door paint needs higher solids and UV-resistant binders. The coverage rate drops from 400 sq ft/gal (interior) to 300 sq ft/gal (exterior), and rougher weathered surfaces absorb 10-15% more. For a 6-panel exterior front door (both sides, 2 coats, including edges), plan for 1 quart of exterior enamel.
Door Paint Cost Calculator Example
For 8 interior 6-panel doors, both sides, 2 coats:
- Surface area: 8 doors x (20 sq ft x 1.2 x 2 sides + 6 sq ft edges) = 432 sq ft
- Paint needed: 432 x 2 coats / 400 = 2.16 gallons
- Round up to 3 gallons (extra for touch-ups over the life of the paint job)
- Door paint cost: 3 gallons x $70/gal = $210 (about $26 per door)
Tips That Save Paint and Money
- Buy quarts for single-door projects. A quart covers one door on both sides with two coats. Quart-size premium enamel is roughly $20-30 (vs $70+ for a full gallon).
- Prime raw or stained wood. A dedicated primer (Stix, Zinsser B-I-N, Bulls Eye 1-2-3) holds topcoat much better than topcoat-only applications.
- Lay the door flat on sawhorses. Brushing or rolling a door in place creates runs and drips that waste paint. Flat application uses less product and gives a smoother finish.
- Use a foam mini-roller plus a brush for panels. The combo is faster and uses less paint than brushing alone. Buy one 4-inch mini-roller for flat faces and a 2-2.5 inch angled sash brush for panels and profiles.
- Exterior doors need primer on sanded or stripped areas. Skipping primer under exterior topcoat cuts paint life by half.