Estimate wall and ceiling square footage, deduct doors and windows, calculate exact topcoat gallons, quarts, and primer requirements with professional coverage accuracy.
| Item Description | Area / Surface | Units to Order |
|---|
Professional estimating divides net paintable surface square footage by spreading rate per gallon multiplied by the desired coat count.
Running out of paint with one wall left forces an extra store trip. Worse, paint mixed in different factory batches can exhibit slight pigment variance ("picture framing"), ruining a seamless finish.
Ignoring doors, sliding patio portals, and large windows inflates estimated paint needs by 15% to 30%, wasting \$50 to \$150 per room on surplus paint that languishes in basements.
Applying topcoat directly over new drywall or joint compound causes suction variations and dull "flashed" spots. Our calculator prompts for primer when required to lock the substrate.
Buying a full gallon when you only need an extra pint is a waste of money. Our algorithm outputs exact whole gallon and quart packaging recommendations to minimize project expense.
Measure length, width, and ceiling height to compute total gross wall surface area.
Count doors (21 sq ft each) and windows (15 sq ft each) to automatically subtract non-painted area.
Toggle optional ceiling painting to separate ceiling flat paint from wall sheen requirements.
Choose 1 coat for refreshing similar shades, or 2 coats (recommended) for uniform film build.
Review whole gallon and quart packaging breakdowns and copy the shopping takeoff.
Standardizes passage doors at 21 sq ft (3' × 7') and double-hung windows at 15 sq ft (3' × 5'), eliminating manual tape measure subtractions.
Eliminates wasteful over-purchasing by splitting fractional requirements into exact gallons and single quarts (e.g. 2 gal + 1 qt instead of 3 full gallons).
Keeps flat ceiling paint and stain-blocking primer in distinct purchasing buckets from satin or eggshell wall topcoats.
Dynamic vector diagram illustrates total wall span with proportionally positioned doors and windows for visual layout verification.
| Paint Finish / Sheen | Spreading Rate (sq ft/gal) | Durability & Washability | Recommended Room Applications |
|---|---|---|---|
| Flat / Matte (0-5% gloss) | 350 – 400 sq ft | Low washability (hides drywall flaws) | Ceilings, low-traffic adult bedrooms |
| Eggshell (10-25% gloss) | 350 – 400 sq ft | Moderate washability, soft luster | Living rooms, dining rooms, guest bedrooms |
| Satin (25-35% gloss) | 350 – 380 sq ft | High moisture resistance, easy clean | Hallways, kids' rooms, kitchens, bathrooms |
| Semi-Gloss (35-70% gloss) | 300 – 350 sq ft | Very high durability, scrubbable | Doors, baseboards, window casings, trim |
| Drywall Primer / Sealer | 250 – 320 sq ft | Porous absorption barrier | Raw taped drywall, masonry, bare pine lumber |
Authoritative decorating standards for wall measurement, opening deductions, and gallon requirements.
