Rounding seems simple until you need significant figures instead of decimal places, or need banker’s rounding for financial precision, this calculator handles every common rounding scenario.

How to use this calculator

1. Choose your mode: Decimal Places or Significant Figures.
2. Enter your Number and the target precision.
3. Choose a Rounding Method: standard (half up), round down (floor), round up (ceiling), or half to even (banker’s).
4. Read the Rounded Result and the calculation breakdown.

What this calculator does

Rounding looks at the digit just past the target place. 5 or higher rounds up (in standard rounding); below 5 rounds down. This calculator supports rounding to a specific number of decimal places (including negative values for rounding to tens, hundreds, etc.) or to a specific number of significant figures, using your choice of four rounding methods.

Why banker’s rounding exists

Standard “round half up” rounding introduces a small systematic upward bias when applied repeatedly across many values ending in exactly .5, since every one of them rounds up rather than splitting evenly. Banker’s rounding (round half to even) eliminates this bias by rounding .5 values to whichever neighboring digit is even, roughly half the time up and half down across many values, which is why it’s the standard in many financial and statistical computing contexts where repeated rounding bias matters.

Decimal places vs significant figures

Rounding to decimal places counts digits after the decimal point regardless of the number’s overall magnitude, while rounding to significant figures counts meaningful digits starting from the first non-zero digit, which behaves differently for very large or very small numbers, 0.004567 rounded to 3 significant figures is 0.00457, not simply truncated at the third decimal place.

Frequently asked questions