📌 Overview

Estimate how many litres of paint you need for a room, accounting for wall area, doors, windows, number of coats and paint coverage.

🎨 Paint Calculator

Estimate how many litres of paint you need for a room, accounting for wall area, doors, windows, number of coats and paint coverage.

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📖 Deep Dive: Paint Calculator

The calculation logic

First find the total wall area: perimeter times ceiling height = 2 times (length + width) times height. Then subtract doors and windows (standard door about 1.8 sqm, standard window about 1.5 sqm). Finally: paint needed(L) = net wall area times coats divided by coverage per liter.

An example

A 4m by 3.5m bedroom with 2.8m ceiling: perimeter 15m, total wall area 42 sqm; minus one door and one window (3.3 sqm) leaves about 38.7 sqm net. Two coats at 11 sqm/L needs about 7.03 L; buying two 5L cans is the safer choice.

Don't forget these

  • Leave a 10% margin for touch-ups, repairs, and later maintenance.
  • Primer is separate: new walls or big color changes need extra primer.
  • Ceiling is separate: area = length times width, usually with dedicated ceiling paint.
  • Dark colors use more paint: vivid red or blue may need 3-4 coats for even coverage.

    • Reminder

    This tool is an estimate; actual usage depends on wall material, tools (rollers save paint vs spraying), and technique. Buy about 10% more than the result.