Calculation of the amount of product you need and follow these practical tips

Buying only what you need will save you more and protect your environment. Follow these brief tips.

We will use the painting of a room as the first example. The first thing to do is calculate the surface area we are going to paint in square metres.

  1. Use a tape measure to measure the length of all the walls. The sum of the metres measured, multiplied by the height of the wall, will give you the total of the room in square metres.
  2. Then measure the surface area of built-in wardrobes, doors and windows (height x width) and subtract this from the total of metres calculated beforehand. These will be the true metres to be painted.
  3. Finally, divide these total metres  by the yield that is indicated on the paint container or consult this on this website by clicking on the technical sheet of each product. This way, you will be able to calculate the amount of paint you will need to carry out your task. Bear in mind that sometimes the total appears per litre and coat and other times the yield appears.

As general guidance, we can consider the following yields by litre and coat:

  • Water-based vinyl paints of 8 to 10 m2
  • Enamels and synthetic varnishes of 12 to 15 m2
  • Sealants of 10 to 12 m2
  • Primers of 8 to 15 m2


Our work can also be painting furniture, railings or any element whose surface area is hard to calculate. In these cases, we recommend following the guidelines below:

What are we going to paint? Will I need? What kind of product must I use?
Internal door inside a flat 500 ml Enamel / Varnish
Terrace or balcony railing (per linear metre) 100 ml Enamel
Outside shutter 1 x 0.8 m (on both sides) 250 ml Enamel / Varnish
Domestic appliance 150 to 300 ml Enamel
Shelving 30 cm deep with three shelves 400 to 500 ml Enamel / Varnish
Garage door on both sides (2,5 x 3 m) 2 l Enamel / Varnish
Radiator (0,80 x 0,5 m) 250 ml Enamel
10 cm skirting board (per linear metre) 14 ml Enamel / Varnish
A wardrobe 250 to 500 ml Enamel / Varnish
A table 200 to 300 ml Enamel / Varnish
A chair 100 to 150 ml Enamel / Varnish
Window on both sides 100 to 125 ml Enamel / Varnish

 Our tips:

  • Before applying, read and follow the instructions on the containers or technical sheets of the products
  • To achieve a good decorative finish and obtain a good degree of protection for the support, wall, wood or metal, at least two coats must usually be applied
  • If the product is very thick and the viscosity needs to be reduced a little, this must always be done with the solvent indicated for each product, or with clean water in the case of water-based paints
  • Always respect drying times between coats
  • Before painting, the supports must be clean, with no loose paint remains, oils or fats that may harm the appearance and adherence of the paint
  • On vertical surfaces, products must be applied as a fine coat to prevent drips
  • Outdoor areas can be painted, provided that the environmental conditions permit it. Avoid days with rain, very high relative humidity (RH> 80%), temperatures over 30ºC or intense wind. Not only do environmental conditions influence drying, but also the final appearance of the film and its properties
  • Indoors, it is appropriate to encourage ventilation to eliminate potential residual odours and improve drying


If you have any questions or would like a consultation, you can call us during office hours on +34 986 343424 or send us an email at