How it works
Scientific notation: a × 10^b, with 1 ≤ |a| < 10 for nonzero values. Engineering notation uses an exponent divisible by 3.
- Choose conversion or arithmetic.
- Enter the number or both numbers and an operator.
- Choose Auto or a significant-figure count.
- Read the notation, full decimal and working.
Worked example: 0.00045 = 4.5 × 10⁻⁴ = 4.5e-4. In engineering notation it is 450 × 10⁻⁶, using the micro prefix. At 3 significant figures, 299792458 becomes 3.00 × 10⁸.
Scientific notation examples
| Number | Scientific notation | E-notation | Engineering notation | SI prefix |
|---|---|---|---|---|
| 123000 | 1.23 × 10⁵ | 1.23e5 | 123 × 10³ | kilo |
| 0.00045 | 4.5 × 10⁻⁴ | 4.5e-4 | 450 × 10⁻⁶ | micro |
| 299792458 | 2.99792458 × 10⁸ | 2.99792458e8 | 299.792458 × 10⁶ | mega |
| 6.022e23 | 6.022 × 10²³ | 6.022e23 | 602.2 × 10²¹ | zetta |
| 1.6e-19 | 1.6 × 10⁻¹⁹ | 1.6e-19 | 160 × 10⁻²¹ | zepto |
| 0.000001 | 1 × 10⁻⁶ | 1e-6 | 1 × 10⁻⁶ | micro |
| −5000 | −5 × 10³ | −5e3 | −5 × 10³ | kilo |
Swipe the table sideways to see the rest.
Things to consider
- Keep the sign on the coefficient.
- Negative exponents describe small values.
- E means times ten to a power, not Euler's number.
- Trailing zeros can show chosen precision.
- Round only the final arithmetic result.
Frequently asked questions
What is scientific notation?
Scientific notation writes a nonzero number as a × 10^b. The coefficient has magnitude at least 1 and less than 10, and b is an integer. For example, 123000 is 1.23 × 10⁵. Zero is shown as 0 with exponent 0 by convention.
How do I convert to and from scientific notation?
Move the decimal point until one nonzero digit remains before it. Moving left gives a positive exponent; moving right gives a negative exponent. To expand notation, move the decimal right for a positive exponent or left for a negative exponent.
What does E-notation mean on calculators and spreadsheets?
E-notation is a compact way to write powers of ten. 6.022e23 and 6.022E23 both mean 6.022 × 10²³. The E does not mean Euler's number. This converter also accepts a x 10^b and a*10^b.
What is engineering notation?
Engineering notation uses an exponent that is a multiple of 3 and a nonzero coefficient with magnitude at least 1 and less than 1000. For example, 123000 is 123 × 10³. Common SI prefixes include kilo for 10³, mega for 10⁶ and micro for 10⁻⁶.
What do negative exponents mean?
A negative exponent divides by a power of ten. 4.5 × 10⁻⁴ means 4.5 divided by 10000, which is 0.00045. The exponent's sign does not determine whether the number itself is negative.
How do significant figures work?
Select 1 to 15 significant figures to round the final value. Exact halfway cases round away from zero. Significant trailing zeros remain in scientific and E-notation: 299792458 at 3 significant figures is 3.00 × 10⁸. Auto preserves terminating decimals exactly; non-terminating division results are labelled and displayed to 15 significant figures.
How do I multiply and divide in scientific notation?
For multiplication, multiply coefficients and add exponents, then normalise. For division, divide coefficients and subtract exponents. For example, (3 × 10⁸) × (2 × 10⁻³) = 6 × 10⁵. For addition or subtraction, align the exponents first. Division by zero is undefined.
How large can the exponent be?
Input and result exponents are limited to −10000 to 10000 to keep the page responsive. Values use exact integer arithmetic rather than floating-point numbers. For conversions between million, billion and other named scales, use the Million to Billion Converter.
Results are estimates for general information only, not financial, medical or professional advice.