Rounding and Significant Figures Checker
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Enter Values
How to use this calculator
- Enter your value.
- Enter the number of significant figures and/or decimal places you need to round to.
- Read the rounded results.
How it works
Significant figures count from the first non-zero digit and capture the precision of a measurement; decimal places count digits after the point and suit a fixed tolerance.
The tool applies standard round-half-up rounding to each, so you can match your answer to the assessment or specification rule.
Worked example
123.456. To 4 significant figures it's 123.5; to 2 decimal places it's 123.46.
Frequently asked questions
Significant figures or decimal places?
Use significant figures to express the reliability of a measurement (e.g. a distance good to 4 sig figs); use decimal places when a specification fixes the precision (e.g. levels to 3 dp / the nearest millimetre).
Should I round during the calculation?
No. Carry full precision through every step and round only the final answer — rounding intermediate values introduces error that can push the result outside tolerance.
Is this official course material?
No. It is free study support mapped to surveying course levels — not official North Metropolitan TAFE content or advice. Always follow your lecturer and the official assessment brief, and check your own working.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.