How can I measure my house to calculate how much paint I need?

To calculate paint needs accurately, you'll need to measure wall surface area and subtract openings like doors and windows - most rooms require 1 gallon per 350-400 square feet of wall space.

Start by measuring each wall's height and width using a tape measure. Multiply these dimensions to get the square footage of each wall, then add all walls together for your total wall area. For rooms with standard 8-9 foot ceilings, you can use a quick formula: room length + room width, multiply by 2, then multiply by ceiling height.

Subtracting openings is crucial for accuracy. A standard door is about 20 square feet, and windows average 15 square feet each, though you should measure large windows individually. Don't forget to measure any built-in cabinets, fireplaces, or other permanent fixtures that won't be painted. For textured walls common in Ottawa homes, add 10-15% extra paint as texture absorbs more coverage.

Coverage calculations depend on paint quality and surface conditions. Premium paints typically cover 400 square feet per gallon on smooth, previously painted surfaces, while budget paints may only cover 300-350 square feet. If you're painting over dark colors with light paint, or painting new drywall, plan for two coats and reduce coverage estimates by 20%. Primer-and-paint combinations popular in Ottawa's renovation market offer good coverage but may require less product overall.

Ottawa-specific considerations include our older homes with plaster walls, which can be more porous and require additional paint. Many heritage homes in areas like the Glebe or Westboro have intricate trim work that increases surface area significantly. If your home was built before 1978, test for lead paint before sanding or scraping - contact Ottawa Public Health for testing information.

For professional accuracy, consider that experienced painters typically order 10-15% extra paint to account for touch-ups and future repairs. This is especially wise in Ottawa where our freeze-thaw cycles can cause minor wall cracks that need touching up. Keep detailed notes of paint colors and brands - Benjamin Moore and Sherwin Williams both have strong local dealer networks in Ottawa for easy color matching later.

When to call professionals: If you're dealing with high ceilings, extensive trim work, or need color consultation for your renovation, painters can provide more precise estimates and ensure proper surface preparation. For whole-home painting during major renovations, professional contractors can coordinate with other trades and ensure proper ventilation during Ottawa's humid summers.

Want to discuss paint selection or surface preparation for your renovation project? We work with trusted painting professionals and can provide guidance on coordinating painting with other renovation work.