Type in a value in decimal or 'e' notation

Examples: 1.67, 0.01, -0.00001602, 1e10, 1.380649e-23. etc.:

We use in this calculator the following concepts:

- Leading zeros are zeros before non-zero numbers. Example: 00054
- Trailing zeros are zeros after non-zero numbers. Example: 54000
- Trapped zeros are zeros placed in between any two non-zero digits. Example: 5001

Here we can see some definitions of significant figures:

- Significant figures are the number of meaningful digits.
- Significant figures are any non-zero digits or trapped zeros. They do not include leading or trailing zeros.
- Significant Figures are the digits that carry meaning in a number and contribute to its precision.
- Significant figures are digits in the number that are absolutely necessary to indicate the quantity of something.

Here are the rules for counting significant figures:

- All the digits from one to nine are always significant. Example: 5238 has four significant figures.
- Trapped zeros are significant. Example: 10234 has five significant figures.
- Leading zeros are not significant. Example: 0.0025 has two significant figures.
- Zeros placed between the dot and the first non-zero digit are not significant if the number is smaller than 1 (it is a particular case of the rule above). Example: 0.069 has 2 significant figures. '0.0' is not significant.
- Trailing zeros at the end of the number after the decimal point are significant. Example: 812.00 has five significant figures. The result 812.00 makes it clear that the measurement is precise to two decimal places.
- Trailing zeros in a whole number are not significant (unless they come from a measurement). Example: 3400 has two significant figures.
- Any numbers in scientific notation are considered significant (including trailing zeros).
- Only zeros: The number 0 has one significant figure. Therefore, any zeros after the decimal point are also significant. Example: 0.00 has three significant figures, 0.000 has four significant figures ans so on.

Number | Significant figures |
---|---|

2 | 1 |

3 | 1 |

30 | 1 |

100 | 1 |

210 | 2 |

357 | 3 |

360 | 2 |

1000 | 1 |

1500 | 2 |

2010 | 3 |

2804 | 4 |

3700 | 2 |

10014 | 5 |

31400 | 3 |

1E+24 | 1 |

0.0001 | 1 |

Number | Significant figures |
---|---|

0.001 | 5 |

0.0030 | 2 |

0.006 | 1 |

0.01 | 1 |

0.02 | 1 |

0.020 | 2 |

0.1 | 1 |

0.51099891 | 8 |

1.00e3 | 3 |

1.60 | 3 |

10.01 | 4 |

100.00 | 5 |

2.00 | 3 |

2.84 | 3 |

30.00 | 4 |

6.02e23 | 3 |

Note that the number of significant figures doesn't depend on the unit of measurement. So, this calculator also answers to questions like:

- How many significant figures in 38 billion kg or kilograms?
- How many significant figures does 38 billion g or grams have?
- How many significant figures in 38 billion m or meters?
- How many significant figures does 38 billion cm or centimeters have?
- How many significant figures in 38 billion ml or milliliters? Etc.