Significant Figures Calculator

Inputs explained

• Number — Type the number exactly as written — trailing zeros after a decimal point count as significant, e.g. 0.004560 has 4 sig figs.
• Round to significant figures — How many significant figures to keep (1–15).

How to use it

1. Fill in the fields above — each input has a hint describing exactly what to enter
2. Press Calculate to get your result instantly, right on this page
3. Copy the result, save the tool to favorites, or share and embed it anywhere

Understanding the result

Example: 0.004560 has 4 significant figures; rounded to 2 sig figs it becomes 0.0046.

Frequently asked questions

Do trailing zeros always count as significant figures? Trailing zeros after a decimal point are significant (as in 0.004560, which has 4 sig figs), but trailing zeros in a whole number without a decimal point are often ambiguous and may not count.

Why does rounding to sig figs sometimes look different from normal decimal rounding? Significant-figure rounding counts meaningful digits regardless of where the decimal point is, so a number like 0.004560 rounded to 2 sig figs becomes 0.0046, not simply cut off after two decimal places.

Is the Significant Figures Calculator free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.

Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.

What information do I need? Just the following: Number, Round to significant figures. Each field includes a hint explaining exactly what to enter.

Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.

Privacy

Everything you enter into the Significant Figures Calculator is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.