Free calculator
How much can spare change cover?
Round each card purchase up to the next dollar and the spare change adds up. See how much of a monthly membership it could pay for.
The average US consumer makes about 31 card payments a month, bills included (Federal Reserve, source below).
Rounding each purchase up to the next dollar. If cents are spread evenly, the average is about 50¢.
Spare change covers
52% of the membership
$15.50 of spare change a month against $30.00 in dues.
A member still pays
$14.50 a month
on top of their spare change
Across 250 members
$46,500 a year
of dues paid by spare change
How this is worked out
Spare change a month is card purchases a month × the average spare change per purchase. Rounding $4.30 up to $5.00 gives 70¢; across many purchases, if the cents land anywhere from 0 to 99, the average is about 50¢.
Share covered is that spare change ÷ the monthly membership, capped at 100%. A member pays the rest. Across your members multiplies the covered amount by members and 12 months.
It assumes every member rounds up every card purchase. Change the purchases figure to match your members.
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Where the starting numbers come from
- The average US consumer makes about 31 card payments a month (16.1 credit and 14.7 debit), counting bill payments as well as purchases — Federal Reserve, 2026 Findings from the Diary of Consumer Payment Choice