Rounding Calculator

The Rounding Calculator lets you round numbers your way whether that means rounding up, down, to the nearest whole, or truncating decimals. It’s fast, simple, and flexible, built for students, teachers, and anyone who needs precision. Just type your numbers in, choose how you want to round, and get instant results.

This tool supports multiple rounding modes and lets you set the number of decimal places. You’ll see the output update live with each change and you can copy everything with one click.

How to Use:

Enter any number per line into the Input Numbers box. You can enter decimals, negatives, or whole numbers.

Use the Options box to adjust rounding:

• Show original toggles whether to display both input and result (2.718 → 2.72)
• Decimal places choose how many digits after the decimal to keep
• Rounding Mode:
  • Nearest (standard rounding)
  • Round Up (ceil)
  • Round Down (floor)
  • Truncate (cut off digits, no rounding)

Click Convert to manually trigger the result, or type and the result flashes live. Click Copy to grab your output for pasting elsewhere.

What Rounding Calculator can do:

This tool is great for:

• Rounding grades and scores
• Adjusting currency values or estimates
• Converting long decimal output to readable formats
• Exploring how different rounding rules affect results

It’s especially useful when you need control over how rounding is applied. Whether you’re teaching, programming, or formatting financials this gives you full control.

Example:

Let’s say you input these numbers:

3.14159  
2.71828  
9.9999  
5.5555

With 2 decimal places, “Show original” enabled, and Rounding Mode: Nearest, the output will be:

3.14159 → 3.14  
2.71828 → 2.72  
9.9999 → 10.00  
5.5555 → 5.56

Switch the mode to Round Up, and the same numbers become:

3.14159 → 3.15  
2.71828 → 2.72  
9.9999 → 10.00  
5.5555 → 5.56

Now change to Round Down:

3.14159 → 3.14  
2.71828 → 2.71  
9.9999 → 9.99  
5.5555 → 5.55

And finally, using Truncate (which just chops without rounding):

3.14159 → 3.14  
2.71828 → 2.71  
9.9999 → 9.99  
5.5555 → 5.55

Whether you’re controlling decimal precision or cleaning up output formats for presentation, this tool handles it all in just a click.

Rounding Calculator Table:

Here’s how this tool rounds numbers under different modes and decimal settings.

Common Use Cases:

Use this when you need fast, flexible rounding that fits your rules not someone else’s. Great for grade books, math problems, spreadsheet cleanup, or any situation where exact rounding behavior matters.