Hair type, scalp, use of styling products, dirt and activity levels are the main determining factors.
Those who are more active, tend to sweat more, thus requiring frequent hair washes.
Oily scalp requires daily washing as compared to dry scalp which needs a weekly wash.
Hair exposed to dirt and pollen might require to be washed every second day to keep it clean.
Use of styling products can lead to buildups on scalp, thereby requiring frequent washes.
Thick hair needs to be washed every three days to keep it clean.
Fine hair needs to be shampooed every other day to enable it to flourish and grow.
Experts suggest it should be washed only once, every 1-2 weeks!