Enter a Number
Plain decimals (0.0000042) and E-notation (4.2e-6) both work.
In Every Notation
| Form | Value |
|---|
About this scientific notation converter
Scientific notation writes any number as a mantissa between 1 and 10 times a power of ten: 384,400 km to the Moon becomes 3.844 × 10⁵ km, and a bacterium one millionth of a meter long becomes 1 × 10⁻⁶ m. It is the standard language of science classes, calculators (the E on the display means “× 10 to the power of”), spreadsheets and engineering datasheets.
Type a number in any form — an ordinary decimal like 0.0000042 or E-notation like 4.2e-6 — and get all four forms at once: scientific notation, E-notation, engineering notation (exponents in steps of three, matching kilo, mega, micro prefixes) and the fully written-out decimal.
In the US, scientific notation is introduced in middle school math and used from algebra through chemistry; worldwide it is simply how SI units stay readable across 30 orders of magnitude.
The converter also handles negative numbers and values typed straight from a calculator screen.
Famous numbers in scientific notation
| Value | Scientific form | Where you meet it |
|---|---|---|
| 299,792,458 m/s | 2.998 \u00d7 10\u2078 | Speed of light, m/s |
| 60,220,000,000,000,000,000,000,000 /mol | 6.022 \u00d7 10\u00b2\u00b3 | Avogadro constant, per mole |
| 149,600,000,000 m | 1.496 \u00d7 10\u00b9\u00b9 | Distance Earth–Sun (1 AU), m |
| 0.000001 m | 1 \u00d7 10\u207b\u2076 | Typical bacterium, m |
| 0.0000000001 m | 1 \u00d7 10\u207b\u00b9\u2070 | Atom diameter (≈1 ångström), m |
| 1,000,000,000 B | 1 \u00d7 10\u2079 | Bytes in a decimal gigabyte |
How to convert by hand
Move the decimal point until exactly one non-zero digit stays on its left. Count the moves: right moves give a negative exponent, left moves a positive one. So 0.0000042 needs six right moves → 4.2 × 10⁻⁶, and 384400 needs five left moves → 3.844 × 10⁵.
Engineering notation keeps the same idea but stops the exponent on a multiple of 3, so it lines up with unit prefixes: 3.844 × 10⁵ = 384.4 × 10³, which reads naturally as 384.4 kilo.
The table above updates live as you type, so you can experiment freely.
How to convert to scientific notation
- Type the number: A plain decimal or E-notation like 6.02e23.
- Read the table: Scientific, E, engineering and ordinary forms appear instantly.
- Check the rules below: The formula box explains the mantissa and exponent rules.
FAQ
What does the E mean on a calculator?
E stands for “× 10 to the power of”. 3E8 means 3 × 10⁸ = 300,000,000, and 4.2e-6 means 4.2 × 10⁻⁶ = 0.0000042.
How is engineering notation different?
Engineering notation restricts exponents to multiples of 3, matching SI prefixes (kilo 10³, mega 10⁶, micro 10⁻⁶, nano 10⁻⁹), so values read naturally with units.
What is standard form?
Standard form is the same thing as scientific notation — the name is common in British schools, while US textbooks usually say scientific notation.
Why use scientific notation at all?
It keeps extreme values readable and comparable: writing 6.022 × 10²³ is safer than counting 20 zeros, and comparing 10⁻¹⁰ m atoms with 10¹¹ m orbits becomes obvious.