FREE · EDUCATION & SCIENCE
Significant Figures Calculator.
Count significant figures, round to any number of them, and multiply, divide, add or subtract with the correct significant-figure rules.
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How to use Significant Figures Calculator
Type a number to count and round it, or switch to Calculate and enter two numbers with an operation. Scientific notation such as 6.02e23 works.
How it works
Counting follows the standard rules. Rounding works on the decimal digits rather than binary floating point. Multiplication and division keep the fewest significant figures; addition and subtraction keep the fewest decimal places.
Example
0.004560 has 4 significant figures and rounds to 0.0046 at two; 3.14159 × 2.1 = 6.6.
Questions about Significant Figures Calculator
Is Significant Figures Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Trailing zeros in whole numbers without a decimal point are reported as ambiguous. Rounding is half away from zero. Everything is calculated in your browser; nothing you type is uploaded. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.