Round any number to a specific count of significant figures — essential for science labs, chemistry homework, and reporting measurements with the correct precision.
How it works
- Enter the number you want to round (e.g. 0.004520 or 12345).
- Set how many significant figures you need.
- View the rounded value and its scientific notation form.
Frequently asked questions
What counts as a significant figure?
All non-zero digits count, zeros between non-zero digits count, and trailing zeros after a decimal point count. Leading zeros do not.
Why do sig figs matter?
They reflect measurement precision. Reporting more digits than you measured implies false accuracy.
How is rounding handled?
Standard round-half-up rules apply at the last retained digit.