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Round numbers to any decimal place with multiple rounding modes
Rounds to nearest value. If exactly halfway, rounds up (e.g., 2.5 → 3)
Enter a number to see rounding result
Most common rounding method. Round to nearest value; if exactly halfway (0.5), round up.
• 2.4 → 2
• 2.5 → 3
• 2.6 → 3
Round to nearest value; if exactly halfway (0.5), round down.
• 2.4 → 2
• 2.5 → 2
• 2.6 → 3
Round to nearest even number when exactly halfway. Minimizes cumulative rounding errors.
• 2.5 → 2 (even)
• 3.5 → 4 (even)
• 4.5 → 4 (even)
Always rounds toward zero. Simply removes decimal places.
• 2.1 → 2
• 2.9 → 2
• -2.9 → -2
Always rounds away from zero. Increases absolute value.
• 2.1 → 3
• 2.9 → 3
• -2.1 → -3
• Half Up: General calculations
• Half Even: Financial, scientific
• Down: Conservative estimates
| Number | Decimal Places | Half Up | Half Even | Down |
|---|---|---|---|---|
| 3.14159 | 2 | 3.14 | 3.14 | 3.14 |
| 2.5 | 0 | 3 | 2 | 2 |
| 3.5 | 0 | 4 | 4 | 3 |
| 4.5 | 0 | 5 | 4 | 4 |
| 123.456 | 1 | 123.5 | 123.5 | 123.4 |
| 99.999 | 2 | 100.00 | 100.00 | 99.99 |
Rounding is the process of reducing the digits in a number while keeping its value similar to the original. It replaces a number with a simpler, approximately equal number based on specified rules. For example, 3.7 rounds to 4, while 3.2 rounds to 3.
The standard rule (half-up) is: if the digit to the right of the rounding position is 5 or greater, round up; if it's less than 5, round down. For example, rounding 2.5 gives 3, while 2.4 gives 2.
Banker's rounding (half-even) rounds to the nearest even number when exactly halfway between two values. This method reduces cumulative rounding bias in large datasets. For example, 2.5 rounds to 2, and 3.5 rounds to 4.
Look at the digit one place to the right of where you want to round. If it's 5 or more, increase the rounding digit by 1; if less than 5, keep it the same. Remove all digits to the right. Example: 3.456 to 2 decimal places = 3.46.
Rounding changes a number to the nearest value based on specific rules, while truncating simply cuts off digits without considering their values. Truncating 3.7 gives 3, but rounding gives 4.
Different methods serve different purposes. Standard rounding works for general use, banker's rounding reduces bias in financial calculations, and truncation provides conservative estimates. The choice depends on the application and desired accuracy.