Number
Round to sig figs
Result (click to copy)
Frequently Asked Questions
What are significant figures?
Significant figures (sig figs) are the meaningful digits in a number that contribute to its precision. They indicate how precisely a value was measured. 4500 has 2 sig figs, 4500. has 4, and 4500.0 has 5.
How do I count significant figures?
Rules: 1) All non-zero digits are significant (1-9). 2) Zeros between non-zero digits are significant (101 = 3 sig figs). 3) Leading zeros are NOT significant (0.004 = 1 sig fig). 4) Trailing zeros after a decimal point ARE significant (2.50 = 3 sig figs).
Why are sig figs important?
Significant figures prevent false precision. If you measure something to the nearest centimetre (28 cm), you can't claim millimetre precision in your calculations. Sig figs communicate the precision of measurements in science and engineering.