๐ข Currency Rounding Calculator
Enter an amount, a rounding unit (1, 10, 100, 1000, etc.), and a rounding rule (round, floor, or ceiling) to calculate the rounded amount. Handy for checking rounding rules on invoices and quotes.
How to use
- Enter the amount.
- Choose the unit (place value) to round to.
- Choose round, floor, or ceiling โ the resulting amount is calculated automatically.
How the calculation works
This tool rounds an amount to the unit you choose (ยฅ1, ยฅ5, ยฅ10, ยฅ50, ยฅ100, ยฅ500 or ยฅ1,000) and shows the difference from the original amount. The amount is divided by the unit, the result is made a whole number by rounding, rounding down or rounding up, and then multiplied by the unit again. Rounded amount = whole(amount รท unit) ร unit Difference = rounded amount โ original amount Rounding goes up from exactly half the unit (ยฅ50 for a ยฅ100 unit) and down below it. Negative amounts are rounded by magnitude and then given their sign, so โยฅ1,250 rounded to ยฅ100 becomes โยฅ1,300. Rounding down always moves to the smaller value, and rounding up always to the larger.
Worked example
Rounding ยฅ1,234 to ยฅ100 Round: 1,234 รท 100 = 12.34 โ 12 โ ยฅ1,200 (difference โยฅ34) Round down: ยฅ1,200 (difference โยฅ34) Round up: ยฅ1,300 (difference +ยฅ66) ยฅ1,250 rounded to ยฅ100 โ ยฅ1,300 (exactly half rounds up) ยฅ12,345 rounded to ยฅ1,000 โ ยฅ12,000
Things to be aware of
- In Japan, businesses may choose how to handle fractions of a yen in consumption tax (round down, up or to nearest). Many shops round down.
- When splitting a bill, rounding each share up collects more than the total and rounding down collects less. Agree in advance who covers the difference.
- Banker's rounding (round half to even), used by some banks and accounting software, is not supported.
FAQ
What's the difference between floor and ceiling?
Floor always drops the remainder below the chosen unit down to zero, while ceiling always rounds up to the next unit whenever there's a remainder. Round (nearest) rounds down or up depending on which side of the midpoint the remainder falls on.
How is the difference calculated?
It's the rounded amount minus the original amount. A positive value means the amount increased; a negative value means it decreased.
Can this be used for tax rounding?
Yes โ enter a tax-inclusive amount or tax amount and set the unit to 1 to check sub-currency-unit rounding (round/floor/ceiling). Note that the actual rounding rule for tax varies by contract or invoicing practice, so always follow the rule that applies to your specific transaction.