We are aware that all of our periods are different. Flows vary, as do the lengths of our periods. For this calculator we have used average figures and these assumptions:

• You have a 28-day cycle which means 13 periods a year.
• You will go through the menopause at 51 years old.
• You will use 22 disposable period products per cycle.
• The average price of a single use period product is £0.15.