What Are Significant Figures?
Significant figures (often abbreviated as sig figs) are the digits in a number that carry meaningful information about its precision. These digits indicate how accurate a measured or calculated value is.
They include:
- All non-zero digits
- Zeros between non-zero digits
- Trailing zeros only when there’s a decimal point
For example, in the number 123, all three digits (1, 2, and 3) are significant, giving it 3 significant figures.
Significant Figures Rules
Follow these simple rules to determine which digits are significant in any number:
Rule #01: All Non-Zero Digits Are Significant
“Any digit from 1 to 9 is always significant, no matter where it appears.”
For Example:
- 2.447 has 4 significant figures (2, 4, 4, and 7).
Rule #02: Zeros Between Non-Zero Digits Are Significant
“Any zeros that are sandwiched between two non-zero digits are always significant.”
For Example:
- 800091 has 6 sig figs.
Rule #03: Trailing Zeros After the Decimal Are Significant
“If zeros come after the decimal and follow a non-zero digit, they are significant.”
For Example:
- 92.00 has 4 significant figures.
Rule #04: Trailing Zeros in a Whole Number with a Decimal Are Significant
“If a whole number ends in zeros and a decimal point is shown, the zeros are significant.”
For Example:
- 540. has 3 significant figures.
Rule #05: Exact Numbers Have Infinite Significant Figures
“Exact values (like those from defined relationships or counting) are considered to have unlimited significant figures.”
For Example:
- 1 meter = 100 centimeters - All digits are exact.
How to Identify Non-Significant Figures
Certain digits do not count as significant figures:
-
Leading zeros: Zeros that appear before the first non-zero digit.
- Example: 0.00200 has only 3 significant figures (2, 0, 0).
-
Trailing zeros without a decimal: These zeros are not significant.
- Example: 45000 has only 2 significant figures (4 and 5).
-
Scientific notation: Only the digits in the coefficient are significant.
- Example: 5.02 × 10⁴ has 3 significant figures (5, 0, 2).
How Many Sig Figs Are There In...?
Check the table below to see the significant figures and digits for common numbers.
| Number | Sig Figs | Decimals | Scientific Notation | E-Notation |
|---|---|---|---|---|
| 0.0010 | 2 | 4 | 1 × 10^-3 | 1e-3 |
| 200 | 1 | 0 | 2 × 10^2 | 2e+2 |
| 8000 | 1 | 0 | 8 × 10^3 | 8e+3 |
| 980 | 2 | 0 | 9.8 × 10^2 | 9.8e+2 |
| 3800 | 2 | 0 | 3.8 × 10^3 | 3.8e+3 |
| 3251.424 | 7 | 3 | 3.251424 × 10^3 | 3.251424e+3 |
| 80.095 | 5 | 3 | 8.0095 × 10^1 | 8.0095e+1 |
| 13.107 | 5 | 3 | 1.3107 × 10^1 | 1.3107e+1 |
| 0.00007 | 1 | 5 | 7 × 10-5 | 7e-5 |
| 833.000 | 6 | 3 | 8.33 × 10^2 | 8.33e+2 |
| 801 | 3 | 0 | 8.01 × 10^2 | 8.01e+2 |
| 825000 | 3 | 0 | 8.25 × 10^5 | 8.25e+5 |
| 1.20 | 3 | 2 | 1.2 × 10^0 | 1.2e+0 |
| 2.5 | 2 | 1 | 2.5 × 10^0 | 2.5e+0 |
| 0.0001 | 1 | 4 | 1 × 10^-4 | 1e-4 |
| 0.00580 | 3 | 5 | 5.8 × 10^-3 | 5.8e-3 |
| 2900 | 2 | 0 | 2.9 × 10^3 | 2.9e+3 |
| 14.600 | 5 | 3 | 1.46 × 10^1 | 1.46e+1 |
| 8.070 | 4 | 3 | 8.07 × 10^0 | 8.07e+0 |
| 0.00169 | 3 | 5 | 1.69 × 10^-3 | 1.69e-3 |
| 102 / 2 | 1 | 0 | 5 × 10^1 | 5e+1 |
| 14.010 | 5 | 3 | 1.401 × 10^1 | 1.401e+1 |
| 16.58 | 4 | 2 | 1.658 × 10^1 | 1.658e+1 |
| 0.01986 | 4 | 5 | 1.986 × 10^-2 | 1.986e-2 |
| 0.0198 | 3 | 4 | 1.98 × 10^-2 | 1.98e-2 |
| 3457.1 | 5 | 1 | 3.4571 × 10^3 | 3.4571e+3 |
| 4.51 - 2.1395 | 3 | 2 | 2.37 × 10^0 | 2.37e+0 |
| 0.000236 | 3 | 6 | 2.36 × 10^-4 | 2.36e-4 |
| 0.169 | 3 | 3 | 1.69 × 10^-1 | 1.69e-1 |
| 18.96 | 4 | 2 | 1.896 × 10^1 | 1.896e+1 |
| 0.0432 | 3 | 4 | 4.32 × 10^-2 | 4.32e-2 |
| 363.75 | 5 | 2 | 3.6375 × 10^2 | 3.6375e+2 |
| 0.00798516 | 6 | 8 | 7.98516 × 10^-3 | 7.98516e-3 |
| 0.024561 | 5 | 6 | 2.4561 × 10^-2 | 2.4561e-2 |
| 82.00756 | 7 | 5 | 8.200756 × 10^1 | 8.200756e+1 |
| 1000 | 1 | 0 | 1 × 10^3 | 1e+3 |
| 0.06900 | 4 | 5 | 6.9 × 10^-2 | 6.9e-2 |
| 0.0025 | 2 | 4 | 2.5 × 10^-3 | 2.5e-3 |
| 3 | 1 | 0 | 3 × 10^0 | 3e+0 |
| 0.00104 | 3 | 5 | 1.04 × 10^-3 | 1.04e-3 |
| 0.046 | 2 | 3 | 4.6 × 10^-2 | 4.6e-2 |
| 3000 | 1 | 0 | 3 × 10^3 | 3e+3 |
| 23.95 | 4 | 2 | 2.395 × 10^1 | 2.395e+1 |
| 0.00097 | 2 | 5 | 9.7 × 10^-4 | 9.7e-4 |
| 35.2 | 3 | 1 | 3.52 × 10^1 | 3.52e+1 |
| 3.00 | 3 | 2 | 3 × 10^0 | 3e+0 |
| 1.0000 | 5 | 4 | 1 × 10^0 | 1e+0 |
| 0.9976 | 4 | 4 | 9.976 × 10^-1 | 9.976e-1 |
| 0.026 | 2 | 3 | 2.6 × 10^-2 | 2.6e-2 |
| 0.037 | 2 | 3 | 3.7 × 10^-2 | 3.7e-2 |
| 0.749 | 3 | 3 | 7.49 × 10^-1 | 7.49e-1 |
| 0.82 | 2 | 2 | 8.2 × 10^-1 | 8.2e-1 |
| 3.5897 | 5 | 4 | 3.5897 × 10^0 | 3.5897e+0 |
| 0.0405 | 3 | 4 | 4.05 × 10^-2 | 4.05e-2 |
| 0.00230 | 3 | 5 | 2.3 × 10^-3 | 2.3e-3 |
| 0.0023080 | 5 | 7 | 2.308 × 10^-3 | 2.308e-3 |
| 0.0340 | 3 | 4 | 3.4 × 10^-2 | 3.4e-2 |
| 2.00120 | 6 | 5 | 2.0012 × 10^0 | 2.0012e+0 |
| 23.023 | 5 | 3 | 2.3023 × 10^1 | 2.3023e+1 |
| 0.0003 | 1 | 4 | 3 × 10^-4 | 3e-4 |
| 0.00340 | 3 | 5 | 3.4 × 10^-3 | 3.4e-3 |
| 0.030 | 2 | 3 | 3 × 10^-2 | 3e-2 |
| 0.001 | 1 | 3 | 1 × 10^-3 | 1e-3 |
| .00020 | 2 | 5 | 2 × 10^-4 | 2e-4 |
| .100 | 3 | 3 | 1 × 10^-1 | 1e-1 |
| .010 | 2 | 3 | 1 × 10^-2 | 1e-2 |
| 2.0034 | 5 | 4 | 2.0034 × 10^0 | 2.0034e+0 |
| 3.4 x 10^4 | 1 | 0 | 3 × 10^4 | 3e+4 |
| 9.0 x 10^-3 | 1 | 3 | 9.0 × 10^-3 | 9e-3 |
| 4.02 x 10^-9 | 1 | 9 | 4.02 × 10^-9 | 4e-9 |
| 0.00010 | 2 | 5 | 1 × 10^-4 | 1e-4 |
| 1.12500 x 10^4 | 1 | 0 | 1.12500 × 10^4 | 1e+4 |
| 1.0200 x 10^5 | 1 | 0 | 1.0200 × 10^5 | 1e+5 |
| 6.02 x 10^23 | 1 | 0 | 6.02 × 10^23 | 6e+23 |
| 6.07 x 10^-15 | 1 | 15 | 6 × 10^-15 | 6e-15 |
| 500 | 1 | 0 | 5 × 10^2 | 5e+2 |
| 6000 | 1 | 0 | 6 × 10^3 | 6e+3 |
| 11.090 | 5 | 3 | 1.109 × 10^1 | 1.109e+1 |
| 0.01249 | 4 | 5 | 1.249 × 10^-2 | 1.249e-2 |
| 1.21 × 10^-3 | 1 | 3 | 1 × 10^-3 | 1e-3 |
| 1.625 × 10^-3 | 2 | 0 | 1.3 × 10^1 | 1.3e+1 |
| 0.000000043 | 2 | 9 | 4.3 × 10^-8 | 4.3e-8 |
| 4.5e7 | 2 | 0 | 4.5 × 10^7 | 4.5e+7 |
| 14468.98263 | 10 | 5 | 1.446898263 × 10^4 | 1.446898263e+4 |
How to Use the Significant Figure Calculator?
Using our Sig Fig Calculator is quick and easy:
- Open the calculator on your browser.
- Enter the number or math expression you want to analyze.
- (Optional) Enter how many significant figures to round to.
- Click the "Calculate" button.
You’ll instantly get:
- The number of significant figures
- The significant digits
- The scientific notation
- The E-notation (if applicable)
What Can You Do With the Sig Fig Calculator?
Our calculator supports multiple mathematical operations while preserving significant figures, making it useful for scientific and engineering calculations.
You can:
- Perform addition (+), subtraction (−), multiplication (×), and division (÷)
- Convert numbers into scientific notation or E-notation
- Use parentheses for complex expressions like (2.3 × 4.1) ÷ (1.2 + 0.5)
- Apply functions like log, ln, and more
Frequently Asked Questions (FAQs)
Is zero a significant figure?
Yes, zero can be significant, but it depends on its position in the number.
Does 0.510 have 3 significant figures?
Yes, 0.510 has 3 significant figures:
- 5 (non-zero)
- 1 (non-zero)
- 0 (trailing zero after a decimal, making it significant)
How many significant figures are in 1000.0?
The number 1000.0 has 5 significant figures.
What types of numbers have unlimited significant figures?
Exact numbers (like defined conversions or counted values) have unlimited sig figs because they are not approximations.
How many significant figures in 0.01?
0.01 has 1 significant figure because the leading zeros are not counted.
References
The following authoritative sources were referenced to ensure accuracy and clarity: