Making change sounds trivial until there’s a line at the register. This calculator gives the exact change due, splits it into the fewest bills and coins your drawer actually holds, and lists the pieces in “count back” order so you can hand them to the customer the way experienced cashiers do.
How to use the change calculator
- Enter the amount due (the total including tax).
- Enter the amount paid by the customer.
- Tick Give $2 bills or Give $1 coins and half dollars if your drawer stocks them.
- Choose the largest bill in the drawer; many stores keep $50 and $100 bills under the tray.
- Read the change on the tape, the breakdown by denomination, and the count-back steps.
Change formula
To break the change into pieces, the calculator works in whole cents and repeatedly takes as many of the largest available denomination as fit, then moves to the next one down. With US denominations this always gives the fewest pieces.
Worked example
A customer’s total is $37.42 and they pay with a $50 bill.
Change = 50.00 − 37.42 = $12.58
Breakdown: one $10 bill, two $1 bills, two quarters, one nickel and three pennies — 9 pieces
Count back: start at $37.42 → 3 pennies ($37.45) → 1 nickel ($37.50) → 2 quarters ($38.00) → 2 ones ($40.00) → one $10 ($50.00)
Common change amounts from a $20 bill
| Purchase | Change | Fewest pieces |
|---|---|---|
| $4.37 | $15.63 | $10, $5, 2 quarters, 1 dime, 3 pennies |
| $7.89 | $12.11 | $10, 2 × $1, 1 dime, 1 penny |
| $12.50 | $7.50 | $5, 2 × $1, 2 quarters |
| $16.99 | $3.01 | 3 × $1, 1 penny |
| $19.26 | $0.74 | 2 quarters, 2 dimes, 4 pennies |
Cashier tips
Count back out loud
Counting up from the purchase amount lets the customer follow along and catch mistakes immediately. It also prevents the classic “short-change” confusion when a customer changes their mind about how they’re paying.
Keep the payment visible
Leave the customer’s bill on the ledge of the drawer until the change is handed over, so there is no dispute about whether they paid with a $20 or a $50.
Accept odd amounts
If a customer pays $50.42 for a $37.42 total, they want round change back: here, exactly $13. Enter the full amount paid and the calculator will give the simplest breakdown.
Rounding without pennies
Some businesses round cash totals to the nearest nickel. If yours does, round the amount due first, then enter it here.
To tally the drawer at the end of the shift, use the money counter. To add sales tax to a price before ringing it up, try the sales tax calculator.
The change breakdown assumes standard US denominations and an unlimited supply of each; adjust if your drawer runs low on a coin.
Frequently asked questions
How do I calculate change?
Subtract the amount due from the amount paid. A $37.42 purchase paid with a $50 bill needs $12.58 in change: a $10 bill, two $1 bills, two quarters, a nickel and three pennies.
What is counting back change?
It is a cashier's method of handing back change by counting up from the purchase amount to the amount paid, starting with the smallest coins. For $37.42 paid with $50, you say 37.45, 37.50, 38, 39, 40 and 50 as you hand back each piece.
Why does the calculator skip $2 bills and half dollars?
Most US cash drawers don't stock them, so they are off by default. Tick the options if your drawer has them and the breakdown will include them.
Is giving the largest bills first always the fewest pieces?
Yes, for US currency. Taking as many of the largest denomination as possible at each step (a greedy method) always produces the minimum number of bills and coins with the standard US denominations.