How many pairs of briefs you need

Short answer: Count on one pair per day plus five in reserve. Washing once a week, that means around twelve to fourteen pairs.

The calculation

Take the number of days between two washes and add five. Washing weekly, seven plus five makes twelve. The five extra cover a busy week, a trip and a pair that is in the wash when you need it.

Why more pairs last longer

Elastic and fibres need to rest between wears. With twelve pairs in rotation rather than seven, each pair lasts noticeably longer because it is washed less often. See bamboo briefs for women.

Divide them by purpose

Some pairs for everyday, one seamless pair for tight trousers, one pair in a skin tone for light clothing and a pair for periods. See bamboo underwear for women and period briefs.

Frequently asked questions

How long does a pair last

With cool washing and no softener, typically one to two years with regular wear.

Should you have a fixed replacement day

It helps. Once a year you can sort out the pairs whose elastic has given up.

Are more pairs more expensive in the long run

No. More pairs in rotation wear more slowly and therefore cost less per year.