Rounding Calculator
Round numbers to decimal places, significant figures, or nearest integers with detailed step-by-step explanations and multiple rounding options.
Enter Number & Rounding Type
Result
Enter a number to see rounding results
Rounding Rules
Basic Rule
• Look at the digit to the right of rounding position
• If ≥ 5: round up
• If < 5: round down
• Replace following digits with zeros
Decimal Places
• Count positions after decimal point
• 3.14159 → 3.14 (2 decimal places)
• Used in money, measurements
Significant Figures
• Count meaningful digits
• Start from first non-zero digit
• 0.00123 has 3 significant figures
• Used in scientific calculations
Place Value
• Round to specific place values
• Nearest 10, 100, 1000, etc.
• 1,234 → 1,200 (nearest hundred)
• Used for estimates, approximations
Examples
Example 1: Decimal Places
Round 3.14159 to 2 decimal places:
Look at 3rd decimal place: 1 (< 5, so round down)
Result: 3.14
Example 2: Significant Figures
Round 0.004567 to 3 significant figures:
First 3 significant digits: 4, 5, 6
Next digit is 7 (≥ 5, so round up)
Result: 0.00457
Example 3: Nearest Hundred
Round 1,234 to nearest hundred:
Look at tens digit: 3 (< 5, so round down)
Result: 1,200
Frequently Asked Questions
Look at the digit immediately to the right of where you want to round. If it's 5 or greater, round up. If it's less than 5, round down. This is called the 'round half up' method.