About Sig Figs Calc
A free, educational significant figures calculator built for students, teachers, and scientists.
Our mission
Sig Figs Calc exists to make significant figures genuinely easy to understand — not just to produce an answer, but to explain the logic behind it. Too many online tools give you a result without telling you why. We built something different.
Every calculation on this site includes a step-by-step breakdown, the rule applied, and links to supporting content that explains the underlying concept. Students should be able to learn from this tool, not just copy-paste answers from it.
What we cover
- Counting significant figures in any number — including edge cases like 1000, 0.00340, and 100.00
- Rounding to a target sig fig count, step by step
- Solving expressions with correct sig figs for addition, subtraction, multiplication, and division
- Converting numbers to scientific notation with correct sig fig counts
- Comprehensive rules pages covering all 7 sig fig rules
- Number-specific worked examples for common test cases
Our standards
All content on Sig Figs Calc is reviewed for accuracy against standard chemistry and physics conventions taught at the high school and university level. We follow the significant figure rules outlined in general chemistry textbooks and used in IUPAC-aligned measurement practice.
If you find an error, please contact us. We take accuracy seriously and will correct mistakes promptly.
For educational use
Sig Figs Calc is designed for educational use. It is not a substitute for professional scientific, medical, or engineering advice. For critical calculations, verify results independently.