About the Scientific Notation Converter
Scientific notation expresses a number as a coefficient times a power of ten, like 2.99792458e8 for the speed of light, which is compact for very large or very small values. This tool converts each number you enter to E notation and also shows its plain decimal form, so you can read both. Convert several at once, one per line.
It is useful for reading numbers from scientific output, spreadsheets and programming logs, and for checking the magnitude of a value at a glance. For thousands-separator formatting instead, use the Number Formatter.
Standard form keeps exactly one non-zero digit before the point, so the coefficient sits between 1 and 10 and the exponent carries the magnitude: 12345.678 becomes 1.2345678e4 and 0.00042 becomes 4.2e-4. Moving the point one place left adds one to the exponent and one place right subtracts one, which is the whole conversion. The exponent doubles as a digit count, since e6 means seven digits before the point.
Precision is the catch. Values run through double-precision floats, which hold roughly 15 to 17 significant digits, so a 20-digit account number or identifier pasted here comes back rounded and should never make the trip. Spreadsheets do the same damage in the other direction, displaying a long numeric code as 1.23457E+14 and losing the original digits once the file is saved. Where exactness matters more than magnitude, keep the value as text.
How to use
- Paste numbers, one per line.
- Read the scientific notation and the plain value.
- Copy whichever form you need.
Common questions
- What does e8 mean?
- Times ten to the eighth power. So 2.99792458e8 is 299,792,458.
- Does it convert from scientific back to plain?
- It shows the plain value alongside the scientific form for every input, including inputs already in E notation.
- How small a number can it show?
- Down to the smallest a double-precision float represents, around 5e-324.