Rounding Calculator
Round a number to any decimal place or whole-number magnitude.
Try an example
3,847.26
About this calculator
How This Rounding Calculator Works
Enter a number and choose the place value to round to — from the nearest thousand down to four decimal places — and the calculator returns the rounded result.
The Rule
This calculator uses standard "round half up" rounding: look at the digit immediately after your chosen place. If it's 5 or greater, the last kept digit rounds up by one; if it's 4 or less, the last kept digit stays the same and everything after it is dropped.
Worked Example
47.863 rounded to 2 decimal places is 47.86, since the digit after the hundredths place (3) is less than 5.
Worked example
3,847.2591 rounded to 2 decimal places is 3,847.26 — the digit right after the cutoff (9) rounds the last kept digit up.
Frequently asked questions
What rounding rule does this use?
"Round half up": if the digit right after your chosen place is 5 or more, the last kept digit rounds up; otherwise it stays the same.
Can I round to the nearest ten, hundred, or thousand?
Yes — choose a negative decimal place (e.g., nearest 100) instead of a positive one.
Why does rounding matter for calculations?
Rounding too early in a multi-step calculation can compound small errors — it's usually best to round only the final result.
Does rounding always round up on a 5?
With this calculator's "round half up" rule, yes — some other systems use "round half to even" (banker's rounding), which can round a 5 down instead.