Round any number to a chosen precision and rounding rule. You can round to a number of decimal places or to the nearest multiple (5, 10, 100, 0.25, and so on), choosing the method that fits — from everyday half-up to banker’s rounding for unbiased totals.
How it works
You set a target — either a number of decimal places or a multiple to snap to — and a method. The tool scales the value to that target, applies the rule, then scales back:
- Round half up — the standard rule; halfway values go to the larger number (2.5 → 3).
- Round half to even (banker’s rounding) — halfway values go to the nearest even number (2.5 → 2, 3.5 → 4), avoiding the upward bias half-up accumulates over many figures.
- Ceiling — always round up. Floor — always round down.
- Truncate — drop the extra digits toward zero.
For nearest-multiple mode, the value is divided by the step, rounded, then multiplied back, so 47 to the nearest 10 becomes 50.
Example
Rounding 2.5 to a whole number shows how the method matters:
| Method | 2.5 → | 3.5 → | −2.7 → |
|---|---|---|---|
| Half up | 3 | 4 | −3 |
| Half to even | 2 | 4 | −3 |
| Ceiling | 3 | 4 | −2 |
| Floor | 2 | 3 | −3 |
| Truncate | 2 | 3 | −2 |
Rounding 47 to the nearest multiple of 10 gives 50; to the nearest 0.25, 2.6 becomes 2.5.
All rounding runs entirely in your browser; nothing is uploaded.