When do zeros count as significant figures?

Zeros between nonzero digits and trailing zeros with a decimal count; leading zeros do not count.

How do I count sig figs in 0.002040?

0.002040 has 4 significant figures.

What rule do I use for addition and subtraction with sig figs?

Match the least number of decimal places in the inputs.

What rule do I use for multiplication and division with sig figs?

Match the least number of significant figures in the inputs.

Does scientific notation change the number of significant figures?

No; count only the digits in the coefficient. For example, 4.00×10^2 has 3 significant figures.

About Significant Figures Calculator

Built for Precision. Designed for Students, Teachers, and Scientists.

At YourSignificantFiguresCalculator.com, we believe every number tells a story but only when written clearly. Our goal is to make it easy for anyone to calculate and understand significant figures with accuracy, speed, and zero confusion.

Who We Are

We are a team of educators, developers, and STEM enthusiasts who care deeply about math, science, and clarity in communication. Our platform is designed for:

Students who want fast, correct answers for homework
Teachers who need reliable tools for classroom demos
Scientists and researchers who care about precision in reporting
Anyone who asks: “How many significant figures should this number have?”

What We Do?

We offer a free, fast, and easy-to-use significant figures calculator online. Whether you need help with:

Counting how many significant digits a number has
Rounding a number to the right number of sig figs
Adding, subtracting, multiplying, or dividing using sig fig rules
You’ll find everything in one place with clear explanations, built-in examples, and no distractions.

Why We Made This Site

Too many online calculators give results without teaching. We built this site to be different.

Here, you not only get the right answer, but you also learn why it’s right. We combine accurate math logic, educational content, and clean design to support anyone learning or teaching significant figures from middle school to grad school.

What Makes Us Different

Always Free : No login, no fees, no popups
Simple Interface: Easy for kids, fast for adults
Education-First: Every calculator is backed by a written guide
Mobile-Friendly: Use it on your phone, tablet, or computer
Updated Frequently: We keep our tools and explanations current

Our Mission

To help students and professionals understand significant figures with confidence.
Whether you’re preparing a lab report, checking your math, or learning for the first time, we give you the right tools fast and free.

Our Vision

To become the most trusted online hub for significant figures calculators, rules, and learning tools helping millions of learners build accuracy and trust in every number they write.

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