Scientific Notation Converter
Convert any decimal number to scientific notation, E-notation, and engineering notation, or convert scientific notation back to an ordinary decimal. The converter below runs entirely in your browser and updates as you type.
Scientific notation converter
How the scientific notation converter works
Type a decimal number into the first tab and the tool instantly shows three representations of the same value. Scientific notation writes the number as a mantissa between 1 and 10 multiplied by a power of ten, for example 3.6722 × 10³. E-notation is the compact form used by calculators and programming languages, such as 3.6722E3, where the E stands for “times ten to the power of”. Engineering notation is like scientific notation, except the exponent is always a multiple of three, which lines up with metric prefixes such as kilo, mega, and milli.
Switch to the second tab to go the other way: enter a value in scientific or E-notation, such as 3.6722e3 or 1.5E-7, and the tool converts it back to an ordinary decimal number. Both tabs recalculate live as you type, so there is no need to press a button, though Convert buttons are provided as well.
The three notation formats
Scientific notation writes a number as m × 10ⁿ, where the mantissa m is at least 1 and less than 10, and n is an integer exponent. To convert 3672.2, the decimal point moves three places left to give 3.6722, so the exponent is 3: 3.6722 × 10³. For a small number like 0.000456, the point moves four places right to give 4.56, so the exponent is −4: 4.56 × 10⁻⁴.
E-notation replaces “× 10” with the letter E, giving the same information in plain text: 3.6722E3 means 3.6722 × 10³, and 4.56E-4 means 4.56 × 10⁻⁴. This is the format most calculators display and the format spreadsheets and programming languages accept as numeric input.
Engineering notation keeps the mantissa between 1 and 1000 instead of between 1 and 10, so the exponent is always a multiple of three. The number 0.000456 becomes 456 × 10⁻⁶, which reads naturally as 456 micro-something, and 299792458 becomes 299.792458 × 10⁶, which reads as about 299.8 mega-something. Engineers prefer this form because each step of three in the exponent matches a metric prefix.
Worked examples
Example 1: 3672.2. Moving the decimal point three places left gives the mantissa 3.6722, so scientific notation is 3.6722 × 10³. E-notation is 3.6722E3. Because 3 is already a multiple of three, engineering notation is also 3.6722 × 10³.
Example 2: 0.000456. Moving the decimal point four places right gives 4.56, so scientific notation is 4.56 × 10⁻⁴ and E-notation is 4.56E-4. For engineering notation the exponent must be a multiple of three, so we use −6: 0.000456 ÷ 10⁻⁶ = 456, giving 456 × 10⁻⁶.
Example 3: 299792458 (the speed of light in metres per second). The decimal point moves eight places left to give 2.99792458, so scientific notation is 2.99792458 × 10⁸ and E-notation is 2.99792458E8. The nearest multiple of three below 8 is 6, and 299792458 ÷ 10⁶ = 299.792458, so engineering notation is 299.792458 × 10⁶.
Example 4: converting back, 1.5e-7. The E-notation 1.5e-7 means 1.5 × 10⁻⁷. Moving the decimal point seven places left gives 0.00000015, which is the ordinary decimal form.
Common mistakes
- Confusing the sign of the exponent. A negative exponent means a small number, not a negative number: 4.56 × 10⁻⁴ is positive 0.000456. The minus belongs to the exponent, not the value.
- Writing the mantissa outside 1 to 10. In proper scientific notation the mantissa must be at least 1 and less than 10, so 36.722 × 10² is not finished — it should be 3.6722 × 10³. Engineering notation is the exception, where the mantissa may run from 1 to 1000.
- Miscounting decimal places. Each place the point moves changes the exponent by exactly one. A quick check: 3.6722 × 10³ must be in the thousands, so if your answer is 36.722 or 367220, recount the places.
- Mixing up E-notation with the constant e. In 3.6722E3 the E means “times ten to the power of”, and has nothing to do with Euler’s number e ≈ 2.718. Typing 3.6722e3 into a calculator gives 3672.2, not 3.6722 × 2.718³.
- Dropping trailing zeros that matter. In 4.50 × 10³ the zero after the 5 is significant — it says the value was measured to the tens place. Writing 4.5 × 10³ loses that information.
Privacy and accuracy
This converter runs entirely in your browser. Nothing you type is sent to a server, stored online, or shared with anyone — the calculation happens locally on your device, consistent with every other CalcNova tool. Results use standard double-precision arithmetic and are displayed with up to ten significant digits, which is more than enough for homework, lab reports, and everyday conversions. Very large or very small inputs are handled the same way as ordinary ones, since the exponent carries the scale.
Frequently asked questions
What is scientific notation used for?
It keeps very large and very small numbers readable. Instead of writing 602200000000000000000000, chemists write 6.022 × 10²³, and instead of 0.00000000006674, physicists write 6.674 × 10⁻¹¹. The exponent shows the scale at a glance.
What is the difference between scientific notation and E-notation?
They carry identical information in different packaging. Scientific notation uses a superscript power of ten (3.6722 × 10³), while E-notation writes the same thing in plain characters (3.6722E3) so it can be typed into calculators, spreadsheets, and code.
When should I use engineering notation instead of scientific notation?
Use engineering notation when the value will be read alongside metric units. Because its exponents are multiples of three, 456 × 10⁻⁶ maps directly onto 456 micrometres and 299.792458 × 10⁶ onto 299.8 megahertz, which scientific notation does not do as neatly.
How do I type scientific notation into this converter?
In the “Scientific to decimal” tab, type it the way a calculator would: a number, the letter E (upper or lower case), then the exponent, for example 3.6722e3 or 1.5E-7. Plain decimals are accepted too.
Why does 0 convert to 0 × 10⁰?
Zero has no meaningful exponent because no power of ten can scale a non-zero mantissa down to zero. By convention the converter shows 0 × 10⁰ (and 0E0), which is the standard way to write zero in these formats.
Does the converter round my numbers?
Results are shown with up to ten significant digits, and trailing zeros added only by the formatting are removed. If you need more digits, for example for a published constant, use the full value from your source rather than the rounded display.