Rounding Calculator
Round any number to decimal places, the nearest 10 / 100 / 1000, or significant figures โ with your choice of rounding rule.
Number to round
How to use this calculator
1. Enter your number
Type any value, positive or negative, with as many decimals as you like. The original number is rounded exactly once using the rule you pick.
2. Choose what to round to
Pick decimal places (0โ6), a place value (nearest 10, 100 or 1000), or a number of significant figures. Each option changes which digit becomes the last kept digit.
3. Pick a rounding mode
The mode decides what happens to the digit being dropped. Half up, half down and half to even only differ when that digit lands exactly on a 5; ceiling, floor and truncate ignore the digit's value entirely.
4. Read the rule applied
Below the result you'll see a short sentence describing exactly how the number was rounded, so you can explain or double-check the answer.
About rounding
What is banker's rounding?
Banker's rounding (round half to even) sends a value ending in exactly .5 toward the nearest even digit, so 2.5 โ 2 and 3.5 โ 4. It cancels out the small upward bias of always rounding halves up and is common in finance and statistics.
Decimal places vs significant figures
Decimal places count digits after the point. Significant figures count meaningful digits starting from the first non-zero digit, so 0.004217 to 2 significant figures is 0.0042.
Ceiling, floor and truncate
Ceiling always rounds toward positive infinity, floor toward negative infinity, and truncate simply cuts off extra digits toward zero. For positive numbers floor and truncate agree; for negatives they differ.