Scientific Notation Converter
Convert any number to scientific notation or expand scientific notation back to standard form. Shows E-notation and significant figures.
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Examples
What Is Scientific Notation
Scientific notation expresses any number as a coefficient between 1 and 10 multiplied by a power of 10. The number 0.000045 becomes 4.5 × 10⁻⁵. The number 12,345,000 becomes 1.2345 × 10⁷. This format is essential in science and engineering where very large (atomic scale) and very small (subatomic) numbers appear constantly.
E-notation in Programming
In code and calculators, scientific notation is written using the letter E: 4.5E-5 means 4.5 × 10⁻⁵. JavaScript, Python, Java and most programming languages accept and produce E-notation for floating-point extremes. When you see 1.23e8 in console output, it means 123,000,000.
Frequently Asked Questions
Move the decimal point until there is exactly one non-zero digit before it. Count the number of places you moved — this is the exponent. If you moved left, the exponent is positive; if right, it is negative. Example: 0.00034 — move the decimal 4 places right to get 3.4, so the result is 3.4 × 10⁻⁴.
Significant figures are the meaningful digits in a number, indicating its precision. In 4.5 × 10⁻⁵, there are 2 significant figures. Leading zeros are never significant (0.00045 has 2 sig figs). Trailing zeros after a decimal point are significant (1.500 has 4 sig figs). In scientific notation, all digits in the coefficient are significant.
The speed of light in a vacuum is approximately 2.998 × 10⁸ metres per second (or about 3 × 10⁸ m/s as a rounded value). In E-notation: 2.998E8. This is why light-year is used as a distance unit — at 3 × 10⁸ m/s, light travels 9.461 × 10¹⁵ metres in one year.
When multiplying two numbers in scientific notation, multiply the coefficients and add the exponents. Example: (3 × 10⁴) × (2 × 10³) = 6 × 10⁷. When dividing, divide the coefficients and subtract the exponents. This makes calculations with extreme values far easier than working with the full numbers.
1 nanometre = 1 × 10⁻⁹ metres. Nanometres are used to measure wavelengths of visible light (400-700 nm), transistor sizes in modern processors (under 3 nm), and molecular bonds. The prefix nano- always means 10⁻⁹.