How Long Do Coins Last in Circulation?

The issue of estimated coin life has been a subject of speculation for a long time. There are limited data and systematic studies about the life of coins. Publicly available information from world mints suggests that coins could remain in circulation for at least 25 or 30 years. There are other sources suggesting that coins could last in circulation much longer and their lifetime could even exceed 50 years.

Assumptions about the yearly attrition rate of coins and the numbers available in literature are between 2% and 5% per year. In this article we attempt to estimate the life of pennies based on analysis of samples of about 1,000 circulated US pennies.

Test methodology

We have acquired samples of different US denominations, including pennies, from commercial banks in the San Diego area. We have used samples of 1,000 coins of each denomination. We have assumed that the distribution of coins in San Diego area is a good representation of what we can find across the USA. To prove that the assumption is correct we may have to collect similar samples from different cities in the USA.