Measure Your Own Space

Tonight, measure a room you know well. Length × width gives floor area. Perimeter × height gives wall area before windows and doors. Compute both in your head, then compare to what you guessed.

The gap surprises most people. A 12 × 14 room has 168 sq ft of floor but 416 sq ft of walls — about 2.5 times the floor-only number a first-timer would jot down, because paint covers two dimensions, not one.

Now add paint math. At 375 sq ft per gallon over two coats: 416 × 2 ÷ 375 ≈ 2.2 gallons. Round up to 3 for trim and touch-ups. The whole calculation takes under two minutes and prevents the two most common mistakes: buying far too much or far too little.