What is it?
The Rounding Calculator rounds a number the way you need. Round to decimal places or significant figures, or see it rounded up, down, to the nearest 10 or 100, and with banker’s rounding.
Who is it for?
Students learning rounding rules, scientists using significant figures, and accountants rounding amounts.
How to use it
- Enter the number.
- Set Decimal places or Significant figures.
- Pick the rounding you need from the results.
The answer appears as you type; there is no Calculate button. Tap Copy result to copy it, or Share on WhatsApp to send it.
Decimal places vs significant figures
- Decimal places count digits after the point: 3.14159 → 3.14 (2 dp).
- Significant figures count from the first non-zero digit: 0.004567 → 0.00457 (3 sf); 123,456 → 123,000 (3 sf). Science and engineering use significant figures.
Which rounding?
- Normal (half up): 2.5 → 3. Schools and most everyday use.
- Up (ceiling): how many buses for 130 people at 50 a bus → 3. Always round up when you can’t have a part.
- Down (floor): how many full boxes you can fill.
- Banker’s rounding: 2.5 → 2, 3.5 → 4. Used in finance and computers to avoid always rounding up, which adds bias over many numbers.
Round only at the end of a calculation; rounding in the middle adds errors.
Errors and how to fix them
- “Enter a number”: the number box is empty.
Open the tool: Rounding Calculator
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.