Rounding Calculator guide
Rounding Calculator: Decimal Places and Significant Figures
Use our rounding calculator to round numbers to decimal places, significant figures or the nearest 10, 100 or 1,000, with different rounding methods.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
Rounding makes numbers simpler while keeping them close to their real value. Our Rounding Calculator rounds any number the way you need.
How to use the calculator (Rounding Calculator)
- Enter the number.
- Choose to round to decimal places, significant figures or the nearest 10, 100 and so on.
- Choose a method.
A table shows the number rounded several common ways.
Rounding methods
| Method | 2.5 becomes | −2.5 becomes |
|---|---|---|
| Round half up (normal) | 3 | −3 |
| Always up (ceiling) | 3 | −2 |
| Always down (floor) | 2 | −3 |
| Half to even (banker's) | 2 | −2 |
Normal rounding looks at the next digit: 5 or more rounds up, 4 or less rounds down.
Decimal places or significant figures?
- Decimal places count digits after the decimal point. 3.14159 to 2 dp is 3.14.
- Significant figures count from the first non-zero digit. 0.0045678 to 3 sf is 0.00457.
A worked example
With the calculator's default settings, 3.14159265 rounded to 2 decimal places is 3.14.
Frequently asked questions
Why use banker's rounding?
Normal rounding always pushes halves up, which can bias big totals. Rounding halves to the nearest even number balances out.
How do I round money?
To 2 decimal places, using normal rounding.
Is 0.5 rounded to 0 or 1?
With normal rounding, 1. With banker's rounding, 0.
Sources and further reading
- GOV.UK: National curriculum in England – mathematicsgov.uk
- Wolfram MathWorld: Roundingmathworld.wolfram.com
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.