Wall Paint Calculator

Painting your home can be exciting, but guessing how much paint you need? Not so much. That’s where our Wall Paint Calculator comes in. It takes out the guesswork and gives you the right amount of paint based on your room size, wall height, and more.

Whether you're painting one room or your entire house, this tool works for square feet, square meters, and even adjusts for doors and windows. It’s designed for everyone from DIY homeowners to interior designers in India or anywhere else.

How to Calculate Wall Paint – Simple Formula

We use a proven method used by professionals:

Formula:

Paint Needed (liters) = ((2 × (Length + Width) × Height) − (Doors × 2) − (Windows × 1.5)) × Coats ÷ Coverage

Here’s what each part means:

• Length, Width, Height: The room dimensions.
• Doors and Windows: Subtract area that doesn’t need painting.
• Coats: How many paint layers (usually 2).
• Coverage: How many square meters a liter of paint covers (usually 10 m²).

You can also add 10% extra for wastage to be safe.

How to Use the Wall Paint Calculator

Using our calculator is super easy. Just:

1. Enter the length, width, and height of your room.
2. Pick your unit: meters, feet, inches, or centimeters.
3. Add how many doors and windows you have.
4. Choose the number of coats you want.
5. The calculator tells you:
   - Total wall area
   - Area not to be painted
   - Final paintable area
   - Paint required in liters (with wastage included)

Need to know how many gallons? The calculator can convert that too!

Will It Work for My Room Size?

Yes! You can use this calculator for:

• A small 10x10 room
• A 12x12 room
• A whole 1500 sq ft house interior
• And even custom walls like in a studio, bathroom, or hallway

Example:

A 12x12 room with 3-meter-high walls, 1 door, and 2 windows, 2 coats:

Total Wall Area = 2 × (12 + 12) × 3 = 144 m²  

Unpaintable Area = (1×2) + (2×1.5) = 5 m²  

Paintable Area = 144 − 5 = 139 m²  

Paint Needed = (139 × 2) ÷ 10 = 27.8 liters  

Final with Wastage = 27.8 × 1.10 = 30.58 liters  

Recommended Buy = 31 liters

Final Verdict

Our wall paint calculator saves time, money, and stress. Whether you’re painting a bedroom, living room, or your entire house, you’ll know exactly how much paint you need. No more overbuying. No more running out mid-wall.

It works in meters and feet, handles interior calculations, and suits everyone from home DIYers to pros in India or around the world.

Try it once and you’ll wonder how you ever painted without it!

Frequently Asked Questions

How do I calculate how much paint I need for my walls?

Use the formula:

Paint = ((Wall area − Doors and Windows) × Coats) ÷ Coverage

Or simply use our wall paint calculator.

How much paint is needed for a 12x12 room?

It depends on the height and number of coats. On average, for 8 ft walls and 2 coats, you’ll need around 1 gallon.

Will 1 gallon of paint cover a 10x10 room?

Yes, if you're doing one coat on 8 ft walls, 1 gallon should be enough.

How many gallons of paint for a 1500 sq ft interior?

Usually, for 2 coats and average coverage, you’ll need 10–12 gallons, depending on ceiling height and wall conditions.

Is this calculator suitable for square feet and meters?

Yes! You can enter your room size in either square feet or square meters the tool handles both.