Free Online Scientific Notation Converter
Convert numbers to and from scientific notation.
Accepts plain decimals, 4.25e-11, or 4.25 × 10^-11. Commas are
ignored, so 1,250,000 works too.
How the conversion works
- Enter a number to see the conversion steps.
About the Scientific Notation Converter
Scientific notation writes a number as a coefficient multiplied by a power of ten. It keeps very large and very small values readable and makes the number of significant digits obvious. This converter works in both directions: it turns an ordinary decimal into scientific notation and expands scientific notation back into a full decimal string. It also shows engineering notation, where the exponent is always a multiple of three.
Reading the coefficient and exponent
Standard scientific notation uses a coefficient from 1 up to (but not including) 10. The number 4.25 × 10-11 means 4.25 multiplied by ten to the negative eleventh power, which is 0.0000000000425. A positive exponent produces a large number, a negative exponent produces a value smaller than one, and an exponent of zero leaves the coefficient unchanged. The sign of the original number is carried by the coefficient.
Why the tool avoids floating-point rounding
JavaScript numbers are binary floating-point values, so they cannot represent every decimal exactly. If the converter multiplied and divided those numbers internally, a value such as 0.1 could pick up a long tail of digits. Instead this tool parses the input into a sign, a digit string, and a decimal exponent, then shifts the decimal point by editing the string. The result is the decimal you typed, not a binary approximation of it. That matters for scientific work, for homework, and for very small measurements where every digit is meaningful.
Scientific versus engineering notation
Both forms are valid, but they group digits differently. Scientific notation always places one non-zero digit before the decimal point. Engineering notation places one to three digits before the point and restricts the exponent to multiples of three, which line up with SI prefixes such as kilo (103), mega (106), milli (10-3), and micro (10-6). An engineer reading 12.5 × 103 immediately sees 12.5 thousand, while 1.25 × 104 expresses the same quantity in standard scientific form.
Practical uses
- Astronomy and chemistry values such as distances, masses, and molar counts.
- Electronics measurements in microamps, millivolts, and kilohertz.
- Checking homework answers where the coefficient must sit in the correct range.
- Converting data exports that use
enotation into plain numbers.
Frequently asked questions
Why is my expanded answer longer than the scientific form?
A negative exponent moves the decimal point to the left, so small values need leading zeros. For example, 4.25 × 10-11 expands to 0.0000000000425, which contains ten zeros between the point and the first non-zero digit.
What happens to trailing zeros?
Trailing zeros after the decimal point are removed from the coefficient, and whole-number trailing zeros are folded into the exponent. The value is unchanged, but the display becomes minimal. The significant-digit count shown is based on the digits you entered before normalization.
Can I paste a number with thousands separators?
Yes. Commas are stripped before parsing, so 12,500,000 is read as 12500000. Spaces around multiplication signs are also accepted, including forms such as 3 × 10^8.