# Paint Calculator for Doors

Paint calculator for doors splits your project into interior, exterior, and closet doors. Returns gallons needed, quart alternatives, and paint cost for 2025.

## What this calculates

A whole-house door repaint uses 2-3 gallons of enamel, but a single front door fits in 1 quart. This paint calculator for doors splits your project into interior, closet, and exterior buckets because each uses a different coverage rate and may need a different paint type. The output tells you exactly how many gallons (and which type) to order.

## Inputs

- **Interior Doors** — min 0, max 50 — Bedroom, bath, and hallway doors (paint both sides typically)
- **Closet Doors** — min 0, max 50 — Closet doors are usually painted on one side only (the hallway side)
- **Exterior Doors** — min 0, max 20 — Front, back, and garage-to-house doors (both sides, weather-rated enamel)
- **Door Style** — options: Flat slab (smooth, least paint), Panel (6-panel or 2-panel, most common), Shaker (flat panels + rails, modern), French / glass (paint only frame) — Panel and shaker doors need ~20% more paint than flat slabs
- **Include Door Jambs and Casing** — Adds ~6 sq ft per door for jamb sides + head + casing on both sides
- **Number of Coats** — min 1, max 4 — 2 coats standard; 3 for raw wood or major color change
- **Paint Price per Gallon** ($) — min 0 — Interior door enamel $55-90/gal, exterior $70-100/gal

## Outputs

- **Total Doors**
- **Total Paint Area** (sq ft) — All sides of all doors plus jambs and casing
- **Interior Paint Needed** (gal) — Use interior enamel (400 sq ft/gal coverage)
- **Exterior Paint Needed** (gal) — Use exterior enamel (300 sq ft/gal coverage)
- **Total Gallons to Order** (gal)
- **Purchase Recommendation** — formatted as text
- **Total Paint Cost** — formatted as currency

## Details

## How the Paint Calculator for Doors Works

The tool separates three categories because they have different paint requirements:

1. **Interior doors** (bedroom, bath, hallway): both sides, interior trim enamel, 400 sq ft/gal coverage.
2. **Closet doors:** usually painted on the hallway side only (the inside stays factory-primed or is hidden). Same interior enamel.
3. **Exterior doors** (front, back, garage-to-house): both sides, exterior enamel with UV resistance, 300 sq ft/gal coverage and 10% more per coat because weathered surfaces absorb more.

Each door is 20 sq ft per side (3'0" x 6'8"). Panel and shaker doors add 15-20% to the paint area because the recessed panels and rails create more surface. Jambs and casing add 6 sq ft per door if you paint them.

## Paint Needed for a Whole-House Door Repaint

A typical 3-bedroom / 2-bath house has about:

- 10 interior doors (bedrooms, baths, hallways)
- 4 closet doors
- 2 exterior doors

With 6-panel doors painted both sides (closets one side), 2 coats, including jambs: about 770 sq ft of paint area. That needs 3.2 gallons of interior enamel plus 0.8 gallons of exterior enamel. Round up to 4 gallons interior and 1 gallon exterior (or 3 quarts for exterior to save).

## Paint Cost for Doors (2025)

| Brand | Product | Retail / gallon |
|-------|---------|-----------------|
| Benjamin Moore Advance | Waterborne alkyd | $75-90 |
| Sherwin-Williams ProClassic | Acrylic enamel | $70-85 |
| PPG Breakthrough! | Urethane acrylic | $60-75 |
| Behr Alkyd Semi-Gloss | (Home Depot) | $50-65 |
| Valspar Signature | (Lowe's) | $45-60 |

At $70/gallon, a whole-house door repaint runs about $140 in interior paint plus $20 in exterior quart = $160 total, or $11-12 per door.

## Quarts vs Gallons

A gallon covers 400 sq ft (interior) or 300 sq ft (exterior). A quart covers 100 / 75 sq ft. Here's when to pick each:

| Project | Paint needed | Buy |
|---------|--------------|-----|
| 1 door (both sides, jambs, 2 coats) | ~90 sq ft / 0.23 gal | 1 quart |
| 1 exterior door | ~95 sq ft / 0.32 gal | 1 quart |
| 3-4 interior doors | ~300 sq ft / 0.75 gal | 1 gallon |
| 8+ interior doors | 600+ sq ft / 1.5+ gal | 2+ gallons |

Quarts are almost always cheaper per project than gallons when you need less than 1 gallon, even though they cost more per ounce.

## Interior vs Exterior Door Paint

Do not use interior paint on an exterior door. Interior enamel breaks down in 1-2 years outdoors due to UV and moisture. Exterior door enamel has:

- Higher binder solids (65-75% vs 45-55%)
- UV inhibitors (HALS and UV absorbers)
- Mildewcide
- Better adhesion to weathered or oil-primed surfaces

Products like Benjamin Moore Aura Grand Entrance, Sherwin-Williams Emerald Urethane Trim Enamel, and PPG Advantage Exterior are the standards.

## Tips to Reduce Paint Waste

1. **Pull hinges and latch.** Remove hardware before painting instead of taping around it. Less cutting-in means less waste and no drips.
2. **Lay the door flat on sawhorses.** Runs and sags waste paint. Flat orientation uses less paint and looks better.
3. **Use a foam mini-roller for flat panels and a 2.5-inch angled sash brush for profiles.** Both tools combined use less paint than a 4-inch roller alone.
4. **Between coats, wrap the brush and roller in plastic wrap.** You can reuse them for 24 hours without washing. Big paint savings if you are doing many doors.
5. **Match sheen to use.** Semi-gloss is standard for doors (easy cleaning, modest shine). Satin for modern flat-slab doors in bedrooms. High-gloss for traditional panel doors and exteriors. Flat paint never belongs on a door.

## Frequently Asked Questions

**Q: How does a paint calculator for doors figure gallons?**

A: The calculator multiplies the number of doors by the painted surface area per door, then divides by the coverage rate. A standard panel door is 24 sq ft per side (20 sq ft flat x 1.2 panel factor), so both sides plus jambs is 54 sq ft. At 2 coats and 400 sq ft/gal interior enamel coverage, one door uses 0.27 gallons, or a little over 1 quart.

**Q: Do I use the same paint for interior and exterior doors?**

A: No. Interior enamel breaks down under UV and moisture within 1-2 years outdoors. Use exterior-rated enamel for front, back, patio, and garage-to-house doors. Exterior enamel has UV inhibitors, mildewcide, and higher binder solids for weather resistance. Common exterior brands: Benjamin Moore Aura Grand Entrance, Sherwin-Williams Emerald Urethane Trim Enamel, PPG Advantage Exterior.

**Q: Should I paint both sides of a closet door?**

A: Usually just the hallway side. The inside of a closet stays factory-primed white or is hidden behind stored items. This calculator assumes one side for closet doors; set closet count to zero and add those doors to the interior count if you want both sides painted.

**Q: How much paint for a front door repaint?**

A: One quart of exterior enamel covers a standard front door with two coats on both sides plus jamb and casing. Quart cost runs $20-35. You do not need a gallon unless you are also painting garage-to-house and back doors with the same color.

**Q: How many doors can one gallon paint?**

A: One gallon of interior door enamel (400 sq ft/gal, 2 coats) paints about 4 standard interior doors on both sides including jambs. One gallon of exterior enamel (300 sq ft/gal, 2 coats) paints about 3 exterior doors on both sides. Panel and shaker doors use 20% more paint than flat slabs.

**Q: Is door paint different from wall or trim paint?**

A: Yes. Door enamel is closer to trim enamel than wall paint: high solids (for self-leveling), semi-gloss or satin sheen (for durability and cleaning), and often waterborne alkyd chemistry (combines oil durability with water cleanup). Do not use wall paint on doors; you will see brush marks and the finish will scuff easily.

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Source: https://vastcalc.com/calculators/construction/paint-doors
Category: Construction
Last updated: 2026-04-08