Rounding Calculator
Round any number to the decimal places you need.
How to use the Rounding Calculator
- Enter your number.
- Choose how many decimal places.
- See the rounded value, plus round up and round down.
Round to nearest at the chosen decimal place
About the Rounding Calculator
Enter a number, choose how many decimal places you want, and this calculator shows three answers: the nearest value, the value rounded up (ceiling) and the value rounded down (floor). Seeing all three together is the point — for money, which direction you round often matters more than the rounding itself.
The “nearest” result uses round half up: an exact half goes to the larger value, so 2.5 becomes 3. That is what most people are taught, but it is not the only convention. Many languages and spreadsheets default to banker’s rounding (round half to even), which sends 2.5 to 2 and 3.5 to 4. It looks arbitrary until you add up a long column: half-up pushes every tie the same way and quietly builds an upward bias, while sending ties to the nearest even number cancels that drift out. Accounting and statistical systems often prefer it for exactly that reason.
One genuine caveat: like almost all software, this runs on binary floating point, where some decimals cannot be stored exactly. 1.005 is really held as a hair under 1.005, so rounding it to two places gives 1.00 rather than the 1.01 you might expect. That is not a bug in the arithmetic here — it is how the number was stored before rounding began. See also the average calculator and the percentage calculator.
Frequently asked questions
How does rounding to 2 decimal places work?
It keeps two digits after the decimal point and pushes the rest to the nearest of the two candidates. 3.14159 becomes 3.14, because 3.14159 is closer to 3.14 than to 3.15.
Which rounding rule does this page use?
Round half up: an exact half goes to the larger value, so 2.5 rounds to 3. Round up and round down are shown separately if you need the ceiling or floor instead.
What is banker’s rounding?
Round half to even — ties go to the nearest even number, so 2.5 becomes 2 and 3.5 becomes 4. It exists because always rounding ties upward introduces a small upward bias that accumulates across many numbers. This page does not use it.
Why did 1.005 round to 1.00 instead of 1.01?
Because 1.005 cannot be represented exactly in binary floating point; the stored value is a fraction below 1.005, so the nearest two-decimal value really is 1.00. Every mainstream language behaves this way.
What is the difference between round up and round to nearest?
Round up (ceiling) always goes to the higher value regardless of the digits — 3.14159 becomes 3.15 at two places. Round to nearest picks whichever candidate is closer.