Scientific Notation Converter
Convert numbers to and from scientific notation and see the expanded form.
Scientific notation writes a number as a mantissa between 1 and 10 multiplied by a power of ten, which keeps very large and very small numbers readable. This converter goes both ways: type an ordinary decimal to see its scientific form, or enter a mantissa and exponent to expand it back into a plain number.
For example, 12,345 becomes 1.2345 × 10⁴ because the decimal point moves four places to the left. Going the other way, 1.2345 × 10⁴ multiplies the mantissa by 10,000 to give 12,345 again. The tool also shows E-notation (1.2345e4), the compact form used by calculators and programming languages.
How to use it
- 1Choose “To scientific” to convert a normal number, or “From scientific” to expand one.
- 2In “To scientific”, type any decimal number and read the mantissa and exponent.
- 3In “From scientific”, enter the mantissa and the exponent (the power of ten).
- 4Copy whichever form you need — scientific, E-notation, or the expanded value.
Frequently asked questions
What is scientific notation?+
Scientific notation expresses a number as a value between 1 and 10 times a power of ten. For instance, 4,500 is written 4.5 × 10³ and 0.0021 is 2.1 × 10⁻³. It makes very large or very small numbers easier to write and compare.
What is E-notation?+
E-notation is a text-friendly version of scientific notation where “× 10” is replaced by the letter e. So 1.2345 × 10⁴ is written 1.2345e4. Calculators and programming languages use it because it avoids superscripts.
How do I find the exponent?+
The exponent is how many places the decimal point moves to leave a single non-zero digit in front of it. Moving left gives a positive exponent, moving right gives a negative one. Here it is computed as the floor of the base-10 logarithm of the number.
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