Scientific Notation Calculator
Convert ordinary numbers to and from scientific notation. Your work stays on this device whenever possible.
How to use Scientific Notation Calculator
- Type a value into the 'Number or Notation' field, for example 0.0000456, 3e8, 1200000 or 6.022 × 10^23.
- Open the 'Significant Figures' selector and pick a fixed count from 2 to 8, or keep 'Auto (Detect from input)' if you want the tool to guess.
- Press 'Convert Notation' to build the report.
- Read the three blocks: standard m × 10^n with the E-notation string, the engineering form with an exponent that is a multiple of three, and the SI prefix line.
- Check 'Number Properties' for the sign and base 10 exponent, then use 'Copy result'.
Worked example
Enter 0.0000456 and select '3 Significant Figures'. The tool reports standard form 4.56 × 10^-5, E-notation 4.56e-5, normalized decimal 0.0000456, and engineering form 45.6 × 10^-6 with the prefix line '45.6 micro (μ)'. The exponent -5 sits one step above the nearest multiple of three (-6), so the mantissa is multiplied by 10.
When to use this tool
- A chemistry student rewriting a measured concentration of 0.0000456 mol/L for a lab report.
- An electronics hobbyist expressing a 0.0000456 F capacitor as 45.6 µF.
Important limitations
Standard IEEE 754 double-precision floating-point numbers in JavaScript support up to ~17 significant decimal digits of exact integer precision before scientific rounding occurs.
Frequently asked questions
Which input formats does the field accept?
Plain decimals, E-notation such as 4.56e-5, and typed forms like '4.56 × 10^-5' or '4.56*10^-5'. The multiplication text is rewritten to an 'e' and handed to the number parser, so thousands separators, spaces inside digits and unit suffixes are rejected.
Why does Auto return more digits than I typed?
Auto counts every digit character in the box, leading zeros included, and clamps the total between 2 and 10. Typing 0.0000456 therefore gives 8 figures and 4.5600000e-5. Pick 3 in the selector when you want 4.56e-5.
How does engineering notation differ from scientific notation?
Engineering notation forces the exponent to a multiple of three so it matches metric prefixes. The mantissa then runs from 1 up to 999 instead of 1 up to 10, which is why 4.56 × 10^-5 becomes 45.6 × 10^-6.
What happens with extreme exponents?
The prefix line only names femto (10^-15) through peta (10^15); anything else prints 'No standard SI prefix'. The normalized decimal line is replaced by a notice at an exponent of 16 or more, and values beyond roughly 1.8e308 are refused as not finite.
Are the digits exact?
Numbers are 64-bit floating point, good for about 15 to 17 significant digits. A longer input is rounded by the exponent formatter before anything is shown, so the extra digits cannot be recovered from the output.