Significant Figures Calculator

Significant Figures Calculator – Sig Fig

Enter a number or expression (e.g., 3.14 / 7.58 - 3.15). Set “Round to sig fig” to get a rounded value. Results update in real time.

🔢 Number / Expression

Supports +, −, ×, ÷, parentheses and scientific notation (e.g., 5.033e23).

🎯 Round to sig fig

Uses half-up (regular) rounding.

📏 Unit

Tooltips explain each unit (hover options).

🔎 Sig figs –

🧷 Least significant digit –

Decimal notation: –

Scientific notation: –

E-notation: –

Rounded (to – sig fig): –

Rule	Summary
Leading zeros	Zeros to the left of the first non-zero digit (for values < 1) are not significant.
Captive zeros	Zeros between non-zero digits are significant.
Trailing zeros (no decimal)	Trailing zeros in integers without a decimal point are placeholders, not significant.
Trailing zeros (with decimal)	Trailing zeros in numbers with a decimal point are significant.
Add/Subtract	Result is limited by the least precise decimal place among operands.
Multiply/Divide	Result is limited by the fewest significant figures among operands.