Scientific Notation Calculator
Type a plain number to rewrite it in scientific notation, or give a mantissa and an exponent to expand it back to standard form. The calculator normalizes the coefficient to a single digit before the decimal point, reports the exact power of ten, and shows both the x 10^n and E notation forms side by side. Negatives keep their sign and zero is handled cleanly.
How to convert scientific notation
- Pick a direction with the tabs: 'Number to scientific' or 'Mantissa and exponent'.
- In 'Number to scientific', type any value such as 0.00045 in the Number field.
- In 'Mantissa and exponent', enter the coefficient in Mantissa and the power of ten in Exponent.
- Read the large scientific notation result at the top of the results panel.
- Check the E notation, mantissa, exponent, and standard form cards below it.
- Use the Copy buttons to grab the scientific form or the standard form.
Examples
Small decimal to scientific notation
0.00045
4.5 x 10^-4
Negative number keeps its sign
-0.0000021
-2.1 x 10^-6
Expand a mantissa and exponent
mantissa 6.022, exponent 23
6.022 x 10^23
Frequently asked questions
What is scientific notation?
Scientific notation writes a number as a mantissa whose absolute value sits from 1 up to just under 10, multiplied by a power of ten, such as 4.5 x 10^-4. It keeps very large and very small numbers compact and easy to compare.
What is E notation and how does it differ?
E notation is the plain-text form used by calculators, spreadsheets, and programming languages, where 4.5 x 10^-4 is written 4.5e-4. The letter e means times ten to the power of, so the value is identical, only the way of writing the power of ten changes.
How does the calculator normalize a number?
It scales the value so the mantissa lands from 1 up to just under 10, then records how many places the decimal point moved as the exponent. It also cleans small floating-point errors by keeping up to 15 significant digits, so results like 4.5 x 10^-4 do not show a trailing string of stray digits.
How are negative numbers and zero handled?
Negative numbers keep the sign on the mantissa, for example -2.1 x 10^-6. Zero is a special case: it returns a mantissa of 0 and an exponent of 0, since there is no power of ten that describes it.
Can I convert from scientific notation back to a plain number?
Yes. Switch to the 'Mantissa and exponent' tab, enter the coefficient and the power of ten, and the standard form card shows the expanded decimal value. The scientific and E notation forms update at the same time.
Why does a very large standard form show up in E notation?
The standard form card mirrors how the underlying number is written by the browser. For magnitudes at or above 1e21, or extremely small values, that written form is itself E notation, for example 6.022e+23. The mantissa and exponent cards still give you the exact clean split.
Is there a limit on how big or small a number can be?
The value must be a finite number. In practice that means magnitudes up to about 1.8e308 and down to roughly 5e-324, the range of a double-precision float. Beyond that the input is treated as infinite and rejected.
Do I need to enter the mantissa already normalized?
No. You can enter a mantissa like 60.22 with an exponent of 22 and the calculator will re-normalize it to 6.022 x 10^23. It always reports the standard single-digit form regardless of how you type the coefficient.
Is my input private?
Yes. Every conversion runs locally in your browser with no data sent to a server, so the numbers you enter never leave your device.
Learn more
- Scientific notation and E notation explained
How the mantissa and exponent split works, why the coefficient stays between 1 and 10, and how to read powers of ten in everyday science.
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