Paint Calculator – Find Out Exactly How Much Paint You Need
Starting a new painting project? Estimating the right amount of paint can be tricky. Buy too little, and you’ll run out halfway through; buy too much, and you’ll waste money. Our paint calculator takes the guesswork out of your planning. Simply enter your wall measurements, number of coats, and any excluded areas like doors or windows—and get an instant, accurate paint estimate in liters or gallons.
How to Use the Paint Calculator
Our room paint calculator is designed for convenience and precision. Follow these simple steps:
- Select a measurement unit: Choose between meters (m) or feet (ft) to suit your preference.
- Enter wall dimensions: Input the height and length of each wall. You can add multiple walls for a full-room estimate.
- Include doors and windows: Add the number of openings to automatically subtract their area from the total paintable surface.
- Choose number of coats: For best results, select two coats for even coverage.
- Get your results: Instantly see the total paint required, along with wall area, excluded area, and final paintable area.
What Influences Paint Quantity?
Several factors affect how much paint you’ll need. Our paint coverage calculator considers all the following to ensure accuracy:
1. Wall Surface Area
Start with the basic calculation: Area = Length × Height. The calculator automatically adds up the total for all walls you enter.
2. Non-Paintable Areas
Doors and windows reduce your total paintable surface. We use standard sizes for quick estimation:
- Door: around 1.9 sq. meters (21 sq. ft)
- Window: around 1.4 sq. meters (15 sq. ft)
This ensures your wall paint calculator focuses only on the areas that need painting.
3. Paint Coverage
Paint coverage varies by brand and texture, but here’s a general guide:
- 1 liter covers roughly 10 sq. meters (107 sq. ft)
- 1 gallon covers about 37 sq. meters (400 sq. ft)
Note: Porous or rough walls, and darker colors may need more paint.
4. Number of Coats
Applying more than one coat improves durability and color depth. Our calculator multiplies your paintable area by the number of coats for precise results.
Paint Calculation Formula
Here’s the simple logic behind our paint estimator:
- Calculate total wall area (Length × Height × Number of Walls)
- Subtract the area of doors and windows
- Multiply by the number of coats
- Divide by your paint’s coverage rate
Frequently Asked Questions (FAQ)
How much extra paint should I buy?
Always buy about 10% more than your calculated amount. This covers touch-ups, wall texture variations, and future repairs.
Can I calculate paint for ceilings too?
Yes! Just input your ceiling’s length and width as wall dimensions and the calculator will estimate it accurately.
What if my door or window sizes are non-standard?
You can measure them manually using Length × Height and adjust your entries for the most accurate estimate.
Does the calculator work for both interior and exterior walls?
Yes. It’s suitable for both indoor and outdoor surfaces, but keep in mind that exterior paints may have different coverage rates.
Conclusion
Take the guesswork out of your next painting project. With our paint calculator, you can plan efficiently, buy the right amount of paint, and achieve a professional finish—without waste or stress. Whether you’re repainting a single wall or your entire home, this tool helps you paint smart and save money every time.