OneTaskBy Tim King · Updated
Scientific Notation Converter
Standard Form, E Notation and Engineering
OneTask is free, with no sign-up, and built by one person.
If this tool saved you time, a coffee helps keep new ones coming.
How the Scientific Notation Converter works
This scientific notation converter rewrites any number in scientific notation, E notation and engineering notation, and turns any of those back into a plain decimal. Type 0.000045, 6.02e23 or 6.02 × 10^23 and every form appears at once, with the count of significant figures and the matching SI prefix. You can also round to a set number of figures.
Scientific notation writes a number as a value between 1 and 10 multiplied by a power of ten. It keeps very large and very small numbers readable, makes the precision clear and is what calculators, spreadsheets and programming languages print when a number gets too long. In the UK curriculum it is called standard form.
How the scientific notation converter works
The formula is n = a × 10^b, where 1 ≤ |a| < 10 and b is a whole number. To find b, count how many places the decimal point moves; to find a, divide the number by 10^b. E notation writes the same thing as aEb. Engineering notation picks b as a multiple of 3, so a falls between 1 and 1,000 and lines up with SI prefixes such as kilo, mega and micro.
First example. Avogadro's number, 6.02 × 10^23, has 3 significant figures. In E notation it is 6.02e23 and in engineering notation 602 × 10²¹, which matches the prefix Z (zetta).
Second example. 0.000045 moves the decimal point five places right to give 4.5, so it is 4.5 × 10⁻⁵. In engineering notation it is 45 × 10⁻⁶, which is 45 µ (micro).
Third example. The speed of light, 299792458 m/s, rounded to 3 significant figures is 3.00 × 10⁸, or 300 × 10⁶, which is 300 M (mega) m/s.
How many significant figures? Leave the setting on Auto to keep the figures you typed, trailing zeros after a decimal point included. Choose a number to round the result.
Powers of ten from 10⁻¹² to 10¹² as decimals, E notation, engineering notation and SI prefixes
| Power | Decimal | E notation | Engineering | SI prefix |
|---|---|---|---|---|
| 10⁻¹² | 0.000000000001 | 1e-12 | 1 × 10⁻¹² | p (pico) |
| 10⁻¹¹ | 0.00000000001 | 1e-11 | 10 × 10⁻¹² | – |
| 10⁻¹⁰ | 0.0000000001 | 1e-10 | 100 × 10⁻¹² | – |
| 10⁻⁹ | 0.000000001 | 1e-9 | 1 × 10⁻⁹ | n (nano) |
| 10⁻⁸ | 0.00000001 | 1e-8 | 10 × 10⁻⁹ | – |
| 10⁻⁷ | 0.0000001 | 1e-7 | 100 × 10⁻⁹ | – |
| 10⁻⁶ | 0.000001 | 1e-6 | 1 × 10⁻⁶ | µ (micro) |
| 10⁻⁵ | 0.00001 | 1e-5 | 10 × 10⁻⁶ | – |
| 10⁻⁴ | 0.0001 | 1e-4 | 100 × 10⁻⁶ | – |
| 10⁻³ | 0.001 | 1e-3 | 1 × 10⁻³ | m (milli) |
| 10⁻² | 0.01 | 1e-2 | 10 × 10⁻³ | – |
| 10⁻¹ | 0.1 | 1e-1 | 100 × 10⁻³ | – |
| 10⁰ | 1 | 1e0 | 1 × 10⁰ | (none) |
| 10¹ | 10 | 1e1 | 10 × 10⁰ | – |
| 10² | 100 | 1e2 | 100 × 10⁰ | – |
| 10³ | 1,000 | 1e3 | 1 × 10³ | k (kilo) |
| 10⁴ | 10,000 | 1e4 | 10 × 10³ | – |
| 10⁵ | 100,000 | 1e5 | 100 × 10³ | – |
| 10⁶ | 1,000,000 | 1e6 | 1 × 10⁶ | M (mega) |
| 10⁷ | 10,000,000 | 1e7 | 10 × 10⁶ | – |
| 10⁸ | 100,000,000 | 1e8 | 100 × 10⁶ | – |
| 10⁹ | 1,000,000,000 | 1e9 | 1 × 10⁹ | G (giga) |
| 10¹⁰ | 10,000,000,000 | 1e10 | 10 × 10⁹ | – |
| 10¹¹ | 100,000,000,000 | 1e11 | 100 × 10⁹ | – |
| 10¹² | 1,000,000,000,000 | 1e12 | 1 × 10¹² | T (tera) |
How to read the result
- Scientific notation uses superscript powers, ready to paste into a document.
- E notation is the form spreadsheets, calculators and code accept, such as 4.5e-5.
- Engineering notation shows the power as a multiple of 3, alongside the SI prefix.
- Decimal is the full number written out.
FAQ
How do you convert a number to scientific notation?
Move the decimal point until one non-zero digit sits in front of it. The number of places moved is the power of ten: positive if you moved left, negative if you moved right. 45,000 becomes 4.5 × 10⁴.
What is E notation?
E notation replaces "× 10^" with the letter E, so 4.5 × 10⁴ becomes 4.5E4 and 0.000045 becomes 4.5E-5. Calculators, Excel, Google Sheets and most programming languages read and print numbers this way.
What is the difference between scientific and engineering notation?
Scientific notation keeps one digit before the decimal point. Engineering notation uses only powers that are multiples of 3, so the leading part runs from 1 to 999 and maps straight onto prefixes such as kilo, mega and nano.
Is standard form the same as scientific notation?
In the UK, yes: standard form means a × 10^n with a between 1 and 10. In some other countries "standard form" means a number written out in full, so check which meaning a textbook uses.
How do I write negative numbers in scientific notation?
Keep the minus sign in front: −0.0032 is −3.2 × 10⁻³. The sign of the number and the sign of the power are separate; a negative power only means the number is smaller than 1 in size.
See also: all Units tools, Images, Audio & Video, Documents, Data & Code.
Related tools
File Size Converter
Convert any file or drive size into every decimal and binary unit at once.
Mach Number Calculator
Convert speed to Mach and back using the speed of sound at your altitude.
Exponent Calculator
Raise a number to any power, with exact results for big powers.
Log Calculator
Logarithms in base 10, e, 2 or any base, and antilogs.
Rounding Calculator
Round to decimal places or the nearest 10, with five rounding rules.