How do I use an online paint calculator to accurately estimate how many gallons I need for a full interior repaint in my Moncton home?

Online paint calculators are helpful starting points, but they require careful input and NB-specific adjustments to give accurate estimates for your Moncton home interior project.

Most paint calculators work by multiplying your wall square footage by the paint's coverage rate (typically 350-400 square feet per gallon), then factoring in the number of coats. However, these tools often underestimate real-world needs because they assume ideal conditions that rarely exist in actual homes.

Start with accurate measurements of each room you're painting. Measure wall length and height, multiply to get square footage, then subtract windows and doors (typically 20 square feet per standard door, 15 square feet per average window). For rooms with vaulted ceilings, sloped walls, or complex layouts common in older Moncton homes, break the space into sections and calculate each separately. Don't forget to include closet interiors if you're painting those too.

Input the right surface information into the calculator. Smooth drywall typically gets 400 square feet per gallon coverage, while textured walls (common in 1980s-90s Moncton homes) may only get 300-350 square feet per gallon due to the increased surface area. If you're painting over a dark colour with a lighter one, or covering stained areas, you'll need primer plus two finish coats rather than just two coats of paint.

Add 15-20% to the calculator's estimate for real-world factors. Paint gets absorbed differently by various surfaces, you'll have waste from roller loading and brush cleanup, and you'll want extra for future touch-ups. In older Moncton homes with horsehair plaster walls (pre-1950s construction), add an extra 25% because plaster is more porous than modern drywall and drinks up more paint on the first coat.

Account for NB's winter painting advantages when planning your project. Moncton homes with forced-air heating become very dry in winter (below 30% humidity), which actually helps paint dry faster and level better than summer's higher humidity. However, this dry air can cause paint to set up quickly on your roller, so work in smaller sections and keep a wet edge to avoid lap marks.

Consider your paint quality when using calculators. Premium paints like Benjamin Moore Regal or Sherwin-Williams Duration often have better coverage and may stretch further than the calculator suggests, while budget paints may require an extra coat to achieve full coverage and uniform colour. For a whole-house interior repaint in Moncton, investing in quality paint typically means better coverage, easier application, and longer-lasting results.

Don't forget trim, doors, and ceilings in your calculations. Many online calculators focus only on walls, but trim paint (semi-gloss or satin) and ceiling paint (flat white) are separate purchases. A typical 1,500 square foot Moncton home needs 2-3 gallons of trim paint and 3-4 gallons of ceiling paint in addition to the wall paint.

When to hire a professional: If your calculations show you need more than 15-20 gallons total, or if you're dealing with multiple colours, complex layouts, or older home challenges like wallpaper removal, consider getting quotes from local painters. Professional painters buy paint at contractor pricing and have the experience to estimate accurately, often making the cost difference smaller than expected.

Need help finding a professional painter for an accurate in-home estimate? New Brunswick Painting can match you with experienced local contractors who know Moncton homes and can provide detailed material estimates for your specific project.