Scientific Notation Converter

Avogadro's number has 24 digits and the charge on an electron starts with eighteen zeros after the point. Nobody wants to count those by hand. Paste a number in any common form, one per line, and each one comes back in scientific notation, E notation, engineering notation, standard form and LaTeX, each with its own copy button.

The page opens on six values: 602214076000000000000000,0.0000000000000000001602176634, 299792458,6.67430e-11, -0.00042 and 1200. The first two become 6.02214076 × 10²³ and 1.602176634 × 10^-19. No step uses floating-point maths. Every number is kept as a string of digits and a power of ten, so the last digit of a long constant never turns into a 9 or a stray 4.

Worked Example: Avogadro's Number and the 1200 Trap

For 602214076000000000000000 the card reads 9 significant figures, then explains the move: the decimal point travels 23 places left, so the exponent goes up by 23. Engineering notation keeps the exponent a multiple of three, so the same value shows as 602.214076 × 10²¹, which is 602.214076 Z (zetta). The gravitational constant comes out as 66.7430 p and -0.00042 as -420 μ.

The last sample line is the one students lose marks on. 1200 is read as 1.2 × 10³ with 2 significant figures, because zeros at the end of a whole number are placeholders. The card says so and suggests writing 1200. with a point, which keeps all four and gives 1.200 × 10³. The trailing zero in6.67430e-11 is kept for the same reason in reverse: it sits after a decimal point.

Precision, Significant Figures and Limits

• Leave Significant figures blank to keep every digit you typed, or enter 1 to 30 to round. Rounding is half away from zero, so 0.000445 at 2 figures is 4.5 × 10^-4, and 9.996 at 3 figures carries over to 1.00 × 10¹. Anything else shows“Significant figures must be a whole number from 1 to 30.”
• Exponents run from -9,999 to 9,999. Standard form is written out only up to 400 digits; past that the card keeps the scientific forms and says the decimal version is too long to print.
• Up to 200 numbers are converted at once. Copy All as Tablecopies every result as tab-separated columns, which paste straight into Excel or Google Sheets as a grid.
• SI prefixes cover quecto (10^-30) to quetta (10³⁰). Outside that range engineering notation still shows, without a prefix.

Input Formats It Accepts

Plain decimals with or without thousands separators (1,250,000), a leading point (.5), E notation in either case (6.02e23,4.7E-9), and the written form with ×, x or * before 10 and a caret (7.1 × 10^-4). Superscript digits copied from a textbook, as in 6.02×10²³, are read too, and so is the Unicode minus sign. Any other text on a line stops that line with a message naming the line number, while the rest still convert.

The LaTeX row gives 6.02214076 \times 10^{23}, ready for a lab report or an Overleaf document, and the scientific row copies with real superscript characters so it pastes cleanly into Word or a chat.