Math & Scientific
Significant Figures Calculator
Significant Figures: significant Figures Calculator rounds the value to the requested number of significant figures, counting from the first non-zero digit. Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Significant Figures Calculator lets you work through a calculation in seconds: enter your number and significant figures for the result, all worked out locally in your browser.
About this calculator
Significant Figures Calculator rounds the value to the requested number of significant figures, counting from the first non-zero digit. It matters when you need the exact relationship checked quickly rather than worked through by hand. Worked below as 0.004560 has 4 significant figures (the leading zeros don't count; the trailing zero does). — and the calculator on this page repeats exactly that working for your inputs, instantly, and offline after load.
How to use
- Enter a number and how many significant figures.
- Press Calculate to run the significant figures calculator.
- Read the result: the number rounded to that many significant figures.
- Press Reset to clear the significant figures calculator and start again.
Why use Significant Figures Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Based on standard, well-established formulas.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for homework and assignment checks
Significant Figures in tutoring and teaching sessions
Use it for verifying answers from a textbook
Significant Figures in statistics and data coursework
Use it when working through problems
Significant Figures in research and report calculations
Technical notes
Significant Figures Calculator rounds the value to the requested number of significant figures, counting from the first non-zero digit. It supports 1–15 significant figures and uses decimal round-half-up, with ties away from zero; both output forms represent the same rounded value.
Inputs are taken exactly as entered, so check for typos before trusting an answer.
Because it runs locally, results appear instantly with no server round-trip.
FAQ
What are significant figures?
The digits in a number that carry meaningful precision.
What do I enter in the Significant Figures Calculator?
A number and how many significant figures you want it rounded to.
How is 12345 rounded to 3 significant figures?
To 12300.
Does the Significant Figures Calculator send my data to a server?
No — the Significant Figures Calculator runs entirely in your browser, so the numbers you enter never leave your device.
Worked example
0.004560 has 4 significant figures (the leading zeros don't count; the trailing zero does).