How to use the significant figures calculator
Round a number to a chosen number of significant figures. Enter number, significant figures in the fields above; the rounded value is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- x — Number
- s — Significant figures
Worked example
With number = 123.456789, significant figures = 4, the calculator gives rounded value ≈ 123.5.
Frequently asked questions
What is the formula for the significant figures calculation?
Rounded value = Number(x.toPrecision(s)). Here x is number, s is significant figures.
What inputs do I need for the significant figures calculator?
You need number, significant figures. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.