MCPCalc

Paint Coverage Calculator

Calculate gallons of paint needed for a room.

Scratchpad (not saved)

ft
ft
ft
sq ft

What This Calculator Does

Calculate gallons of paint needed for a room.

It combines Room Length, Room Width, Ceiling Height, Number of Doors to estimate Gallons Needed, Total Paintable Area, Net Wall Area (per coat).

Formula & Method

Wall area is A_w=2(L+W)H. Net paint area per coat is A_n=A_w-21D-15N (subtracting doors and windows). Total painted area is A_t=A_n\cdot Coats and gallons are Gallons=\left\lceil10\cdot\frac{A_t}{Coverage}\right\rceil/10.

Notation used in the formulas: R = Gallons Needed; x_{1} = Room Length; x_{2} = Room Width; x_{3} = Ceiling Height; x_{4} = Number of Doors; x_{5} = Number of Windows; x_{6} = Number of Coats.

Method summary: inputs are normalized to consistent units, core equations are evaluated, then secondary values are derived and rounded for display.

Use this calculator for quick scenario analysis. Start with baseline values, change one driver at a time, and compare how sensitive the results are to each input shown above.

Inputs Used

  • Room Length: Used directly in the calculation.
  • Room Width: Used directly in the calculation.
  • Ceiling Height: Used directly in the calculation.
  • Number of Doors: Used directly in the calculation.
  • Number of Windows: Used directly in the calculation.
  • Number of Coats: Used directly in the calculation.
  • Coverage per Gallon: Used directly in the calculation.

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