How much paint do I need?

Whether you are planning to repaint your bedroom or are going to paint all the rooms in your brand new house, this interior paint calculator is here to help you determine how much paint you need. You will be able to find the paint estimation based on the amount of openings or the number of coats of paint. You can also calculate the final cost of paint required!

How to use the calculator

You will have to input some raw data into the paint calculator. It includes:

  • Room dimensions: you need to type in the length, width and height of the room you are going to paint. If your room has a different shape that a rectangular cuboid, you can also input the surface area directly into the paint estimator. The value calculated automatically takes into account only the walls.
  • Doors: you can leave the default dimensions of a door or customize them to fit your needs. Once you will type in the amount of doors in the room, the paint calculator will find their total area automatically.
  • Windows: again, you can choose the default dimensions or type in custom ones. If you have windows of different sizes in your room, you can also calculate the total area manually and input this value into the appropriate box.
  • Number of coats: by default, our calculator finds the amount of paint required for one layer, but you can input the number of coats you plan to use yourself.
  • Paint efficiency: this number should be written on the paint can or product technical data sheet and is expressed in m²/l.
  • Cost per unit: Optionally, you can input the cost of a unit of paint (cost per liter). The paint calculator will automatically find the total cost of paint.

Is the paint estimation accurate?

Obviously, it won’t be a hundred percent accurate. If the surface is porous or rough, it will require additional paint – up to 20%. Similarly, complicated fittings require extra paint.

You also need to add some paint – up to 30% – if you are painting a surface for the very first time, as you need to prepare the wall.

Lastly, our interior paint calculator does not include the ceiling, so, if you want to include it, you need to plan some extra paint for that.

Paint Calculator