Rounding Calculator

Round, round up, or round down a number to a chosen number of digits.

Category: Calculators

When to use?

Use it to round a result to two decimal places, or to round a price up to the nearest 10. You can freely choose the rounding method and the number of digits.

How to use

  • Enter a number.
  • Choose the method (round, round up, round down).
  • Choose the number of digits (decimal places or integer places).
  • The result is shown automatically.

Input Explanation

Digits support both decimal places (positive) and integer places (negative). E.g. 2 → two decimals, −1 → the tens place.

Calculation Basis

It uses the built-in JavaScript Math functions (Math.round, Math.ceil, Math.floor) to round or truncate at the specified place.

Usage Examples

  • Adjust decimal places - Round a calculation result to two decimal places.
  • Round up to the nearest 10 - Round a price up to the nearest 10 to set the payment amount.
  • Unify statistic digits - Align multiple results to the same number of digits for tables or reports.

Examples

  • 3.14159 rounded to two decimals → 3.14
  • 1234 rounded up to the tens place → 1240

Cautions

  • Differences between rounding and truncation methods can produce small differences in the final value.
  • For financial transactions or accounting, the prescribed rounding rules (e.g. rounding down below the won) may differ — check your guidelines.

Guides

Round up, down, and to nearest

Ceiling always rounds the fraction up; floor always rounds it down; rounding goes up at 0.5 and above, down below it.

Applying by digit

To round at the second decimal, look at the third digit to decide. Set a clear rounding basis for amounts, taxes, and inventory counts.

FAQ

What is the difference between round, round up, and round down?

Round uses 0.5 as the threshold; round up always goes higher; round down always goes lower.

Can it handle negative numbers?

Yes, negative numbers are handled correctly.

How far can I set the digits?

You can set decimal places as well as integer places like ones, tens, and hundreds.

Which way does 0.5 round?

In rounding, 0.5 goes up to the larger value. For a consistent direction, choose round up or round down.

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