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Paint Calculator
Planning a room makeover? Use our Paint Calculator to estimate exactly how many gallons or liters you'll need, saving you time and money on wasted materials.
How to Estimate Paint Coverage
The standard rule of thumb for paint estimation is:
1 Liter covers ≈ 10-12 sq m
To calculate manually:
- Measure the perimeter of the room (add all wall lengths).
- Multiply by the ceiling height to get the total wall area.
- Subtract the area of doors (approx. 21 sq ft each) and windows (approx. 15 sq ft each).
- Multiply by the number of coats (usually 2).
- Divide by the coverage rate (350 for gallons).
🖌️ Designer Tips
Don't Skimp on Quality
Cheap paint often requires 3-4 coats to cover well, meaning you end up buying more paint and doing more work. A premium paint often covers in 1-2 coats.
Buy All Paint at Once
To ensure color consistency, buy all your cans at the same time and mix them together ("boxing") in a large bucket before you start. This prevents slight color variations between cans.
— Lisa K., Interior Designer
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⚠️ Common Mistake: Skipping the Primer
Painting directly on bare wall without primer will cost you MORE in the long run. You'll need extra coats, and the paint won't adhere properly. Always prime first, especially on new drywall or when covering dark colors.
Frequently Asked Questions
How much area does one gallon of paint cover?
On average, one gallon of high-quality paint covers approximately 350 to 400 square feet with a single coat. However, rough surfaces like stucco or unprimed drywall may absorb more paint.
Do I really need two coats of paint?
In most cases, yes. Two coats ensure true color fidelity and durability. If you are painting a light color over a dark wall, you might even need a primer plus two coats.
How do I account for windows and doors?
A standard door is about 21 square feet, and a standard window is about 15 square feet. Our calculator allows you to input the number of doors and windows to automatically deduct their area from the total.
Lisa ensures that our coverage estimates reflect real-world painting scenarios and professional standards.