Heavy wearing oil based paints, such as those suitable for a kitchen or bathroom, tend to be slightly thicker in consistency than emulsion paints and therefore do not spread quite so far.
Tips for calculating amount of paint required
1 Litre of Egg Shell or Kitchen & Bathroom paint covers approximately 12 SqM of indoor wall space.
This figure refers to one coat of paint only.
Most paint requires at least 2 coats to throughly cover the wall, and up to 5 coats if painting over a darker colour with a lighter one.
Remember; if you are planning to paint onto newly applied plasterwork, you may need to 'seal the wall' with a 50:50 mix of emulsion and water before applying the first coat. If so this will need to be accounted for when deciding how much paint to purchase.
Paint Calculator
Use the matrix below to help decide how many Litres of Egg Shell, or Kitchen & Bathroom paint you will need.

Further information and useful links