Significant Figures Calculator
Count sig figs, round to N significant figures, and apply sig fig rules to addition, subtraction, multiplication, and division
Significant Figures Calculator
Round to N Significant Figures
Arithmetic with Sig Fig Rules
Sig Fig Rules Reference
Non-zero digits are always significant. (e.g., 456 → 3 sig figs)
Zeros between non-zeros are significant. (e.g., 4006 → 4 sig figs)
Leading zeros are never significant. (e.g., 0.0034 → 2 sig figs)
Trailing zeros after decimal are significant. (e.g., 3.40 → 3 sig figs)
Trailing zeros without decimal are ambiguous. (e.g., 1200 → 2–4 sig figs; use 1.200×10³ for clarity)
Add/Sub rule: Answer has same number of decimal places as least precise number.
Mul/Div rule: Answer has same number of significant figures as least precise factor.
How to Use This Calculator
Enter your input values
Fill in all required input fields for the Significant Figures Calculator. Most fields include unit selectors so you can work in your preferred unit system.
Review your inputs
Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors.
Read the results
The Significant Figures Calculator instantly computes the output and displays results with units. All calculations happen in your browser — no loading time and no data sent to a server.
Formula Reference
Significant Figures Calculator Formula
See calculator inputs for the governing equation
Variables: All variables and their units are labeled in the calculator interface above.
When to Use This Calculator
- •Use the Significant Figures Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations.
- •Use it during the design phase to rapidly iterate on parameters before running detailed finite element simulations.
- •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility.
- •Use it to generate reference data for a technical report or presentation without manual computation.
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