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Rounding calculator

Type a number and choose how to round it: to a number of decimal places, to significant figures or to a multiple. The calculator works with the digits exactly as you type them, so 2.675 correctly becomes 2.68. Programs that round the stored binary value can give 2.67 instead, because 2.675 is not exactly representable.

Round to
Method

With a point or comma, as many digits as you like.

For decimal places: 0 gives a whole number, −1 rounds to tens, −2 to hundreds.

0.05 for cash rounding, 0.5 for half marks, 10 for tens.

Fill in the fields; the answer appears here straight away.

How it works

  1. Enter the values

    Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.

  2. Instant answer

    The answer appears as you type, with the most important intermediate values.

  3. See the working

    Under "How it's worked out" you see the steps, handy for checking your own calculation.

Four ways of rounding

  • Standard: 0 to 4 round down, 5 to 9 round up. For negative numbers a 5 moves away from zero: −2.5 becomes −3.
  • Round up: always towards the larger number, such as the number of boxes you need (2.1 becomes 3).
  • Round down: always towards the smaller number, for example how many times something fits.
  • Banker's rounding: exactly half goes to the even digit (2.5 becomes 2 and 3.5 becomes 4). That stops many roundings from drifting upwards together.

Decimal places or significant figures?

Decimal places count the digits after the point: 3.14159 to 2 decimal places is 3.14. With 0 you get a whole number, with −1 you round to the nearest ten (1,234 becomes 1,230) and with −2 to the nearest hundred.

Significant figures count from the first digit that isn't zero: 0.0012345 to 2 significant figures is 0.0012, and 1,234.5678 to 3 significant figures is 1,230. This is what physics and chemistry use.

Rounding to a multiple

Choose A multiple to round to 0.05 (cash rounding), 0.5 for half marks, or 10, 100 or 1,000 for round figures.

Examples

Number Setting Result
2.675 2 decimal places 2.68
1,234.5678 3 significant figures 1,230
12.37 multiple of 0.05 12.35
7.5 banker's rounding 8
6.5 banker's rounding 6

Which rounding does my software use?

Spreadsheets and most calculators round half up, which is the Standard setting. Python's round() rounds half to even, like Banker's rounding. JavaScript's toFixed works on the binary value, which is why (2.675).toFixed(2) gives 2.67. When two systems disagree by one in the last digit, this is usually the reason.

Rounding and money

Round only once, at the end: rounding every step of a long calculation lets small errors add up. Your VAT is rounded to whole cents by the VAT calculator, and for percentages there is the percentage calculator.

Frequently asked questions

Why does 2.5 round to 3 on one site and to 2 on another?

There are two conventions. Round half up, the *Standard* setting here, takes 2.5 to 3. Banker's rounding takes a half to the nearest even number, so 2.5 becomes 2 and 3.5 becomes 4. Python's round() works this way.

How do I round to the nearest 10 or 100?

Choose *Decimal places* and enter −1 for tens or −2 for hundreds. You can also choose *A multiple* and enter 10 or 100.

What is the difference between decimal places and significant figures?

Decimal places count the digits after the point. Significant figures count from the first digit that is not zero, so 0.0012345 to 2 significant figures is 0.0012, whatever its decimal places.

How do I round money to the nearest 5 cents?

Choose *A multiple* and enter 0.05. 12.37 becomes 12.35 and 12.38 becomes 12.40.