Rounding Calculator – Round Decimals and Whole Numbers
Round a number to a chosen number of decimal places with several tie-breaking rules.
About the Rounding Calculator
What is the Rounding Calculator?
A rounding calculator rounds a number to a chosen precision using the tie-breaking rule you select.
Why use this calculator?
Currency, measurements and statistics all need consistent rounding, and "half up" versus "always up" changes answers at exact midpoints on the last digit.
How to use it
- Enter the number you want to round.
- Choose how many decimals to keep.
- Pick the tie-break mode and read the result.
Formula
Standard positional rounding at the chosen decimal place.
Rounding introduces error; repeat rounding (chaining) can compound it in statistics.
Frequently Asked Questions
What is "round half up" exactly?
A value exactly midway (like 2.5 to 0 places) goes up to 3 rather than staying at 2.
Which mode do banks use?
Accounting often uses "round half away from zero" or half-even to avoid systematic bias across many rows.
What order of operations does this use?
It follows standard PEMDAS/BODMAS rules: parentheses, exponents, multiplication and division, then addition and subtraction.
How precise are the answers?
The calculator uses double-precision floating-point math (about 15 significant digits) and rounds the display. For exact symbolic results use dedicated algebra software.
Can I enter negative numbers or decimals?
Yes. Negative values, decimals and very large or small numbers are all supported unless a field says otherwise.
What does it mean if I get an error?
Errors usually mean an invalid input, such as division by zero or a negative value where only positives make sense. Check your entries and try again.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.