Scientific Notation Converter

How to use the scientific notation converter

1. Type your value in Number. A plain number (123000, 0.00045, 1 200) or a value already in scientific form (6.02 × 10^23, 1.2x10⁻³, 3e8, -4.5E+06) both work.
2. Leave Significant figures empty to keep the precision you typed, or enter a count to round (or pad) the result to that many figures.
3. Read the table: Scientific notation, Engineering notation, E notation, Standard form, SI prefix and the number of Significant figures. Each format has its own Copy button.

Results update while you type; the Convert button does the same thing. The Step by step panel shows how many places the decimal point moves, the resulting exponent, the rounding and the engineering adjustment.

What each notation means

Scientific notation writes a number as a mantissa between 1 and 10 multiplied by a power of ten: 123,000 = 1.23 × 10⁵ and 0.00045 = 4.5 × 10⁻⁴. To get it, move the decimal point until a single nonzero digit is left of it. Each place moved to the left adds 1 to the exponent; each place moved to the right subtracts 1.

Engineering notation only uses exponents that are multiples of 3, so the mantissa lies between 1 and 1000: 1.23 × 10⁵ becomes 123 × 10³. These exponents match the SI prefixes (k = 10³, M = 10⁶, µ = 10⁻⁶, n = 10⁻⁹…), which is why 4.7 × 10⁻⁶ F is read directly as 4.7 µF.

E notation is the version used by calculators, spreadsheets and programming languages: the “× 10” is replaced by the letter E, so 1.23 × 10⁵ is written 1.23E5 and 4.5 × 10⁻⁴ is 4.5E-4. This tool always writes it with a decimal point, the form that code and CSV files expect.

Standard form is the ordinary decimal writing: 1.2 × 10⁻³ = 0.0012.

Significant figures are kept

A converter that works with floating-point numbers turns 1.20 × 10³ into 1200 and loses the information that the measurement had three significant figures. This tool reads the digits exactly as typed:

• Nonzero digits and zeros between them always count.
• Leading zeros (0.004050) only place the decimal point and do not count.
• Trailing zeros after a decimal point count: 0.004050 has 4 significant figures and becomes 4.050 × 10⁻³.
• Trailing zeros of a whole number without a decimal point (1200) are ambiguous. They are not counted by default, and a note tells you the possible range.

When you ask for more figures than you typed, zeros are added and a note reminds you that this claims extra precision. Rounding uses the usual rule: a 5 rounds away from zero, so 9.996 to 3 figures gives 1.00 × 10¹.

Very large and very small numbers

All the work is done on the decimal digits themselves, not on binary floating-point numbers, so nothing is lost to rounding and there is no overflow: 6.02214076 × 10²³⁰⁰ or 1 × 10⁻⁵⁰⁰⁰ convert just as well as 42. Standard form is written out up to 5000 digits; beyond that, only the scientific formats are shown.