Rounding calculator.
Use this free rounding calculator to get fast estimates, compare scenarios, and understand the numbers with clear step-by-step context.
Use the Rounding Calculator.
Results update automatically as you type. No account is required.
Enter your values
About the Rounding Calculator
A rounding calculator rounds a number to a chosen number of decimal places using the method you pick — nearest, round down (floor), round up (ceiling), or truncate. Useful for currency, measurements, and reporting.
How it works
The number is scaled by 10 to the power of your decimal places, the chosen rounding rule is applied, then it is scaled back. "Nearest" rounds 0.5 up; floor and ceil always go down or up; truncate simply drops extra digits.
Reading the result
The headline is your rounded value, with the nearest, rounded-down, and rounded-up versions listed so you can compare the methods.
Note: Calculations run instantly in your browser and use exact mathematical formulas. For very large numbers, results are shown to standard floating-point precision.
FAQ
What is the difference between floor and truncate?
For positive numbers they match, but for negatives they differ: floor of −2.3 is −3, while truncate gives −2 by simply dropping the decimal.
How is 0.5 handled?
The "nearest" method rounds halves up (so 2.5 becomes 3). This is the most common convention, though some fields use banker’s rounding.
Why does rounding sometimes look off?
Computers store decimals in binary, so a few numbers round in surprising ways at high precision. For everyday decimal places the result is reliable.