Scientific Notation Converter
Use this free scientific notation converter to turn any ordinary number into scientific notation instantly. It also shows e-notation and engineering notation, rounds the mantissa to the significant figures you choose, and walks you through the step-by-step decimal shift so you can see exactly how the exponent was derived.
Enter your number
Type a number like 0.00045, 6020000, -7.2, or 6.02e23. Commas are fine. Results update as you type.
Your results
Enter a number and its conversions will appear here.
How to use this calculator
Type any number into the input field — whole numbers, decimals, and negatives all work. You can even paste e-notation directly (like 6.02e23) or include thousands separators (like 6,020,000); the calculator understands both. Results update the moment you type, and the Convert button re-runs the conversion if you ever need it.
Choose how precisely you want the mantissa rounded using the significant-figures selector. The default is 4 significant figures, which is the common classroom and engineering choice. More figures preserve extra precision; fewer keep the result tidy.
Read the main result first — the standard a × 10n form — then compare it with the e-notation and engineering-notation rows below. The step-by-step box at the bottom shows exactly how many places the decimal point moved, so you can check the exponent by hand.
How it works
Scientific notation rewrites any number as a × 10n, where the mantissa a sits between 1 and 10 (or -10 and -1 for negatives) and n is an integer exponent. The exponent is found from the position of the first non-zero digit: it equals floor(log₁₀|x|), the count of places between the current decimal point and where the decimal point must sit to leave a single digit before it. Moving the decimal point to the right makes n negative; moving it left makes n positive.
The mantissa is your number divided by 10n, then rounded to your chosen significant figures. Because floating-point division can leave artifacts (like 4.499999999999999 instead of 4.5), the calculator rounds through toPrecision and re-parses, so the displayed mantissa is exactly what the rounded digits say. If rounding pushes the mantissa to 10 (for example 9.996 rounding to 4 significant figures), it carries over: the mantissa becomes 1 and the exponent grows by 1.
E-notation is the same value written for keyboards and code: 6.02e23 means 6.02 × 1023, where the number after the "e" is the exponent of 10. Engineering notation shifts the same idea to exponents that are always multiples of 3, so the result lines up with metric prefixes: 33,000 becomes 33 × 103 (33 kilo) rather than 3.3 × 104.
Zero is a special case: it has no non-zero digit to anchor a decimal shift to, so it is written as 0 × 100 by convention. Results are exact mathematical conversions, not estimates.
Frequently asked questions
How do you convert a number to scientific notation?
Move the decimal point until exactly one non-zero digit sits in front of it, then multiply by 10 raised to the number of places you moved it. For example, 0.00045 becomes 4.5 times 10^-4 because the decimal moved 4 places to the right, and 6,020,000 becomes 6.02 times 10^6 because the decimal moved 6 places to the left.
What is e-notation?
E-notation is a compact way to write scientific notation that keyboards and calculators understand: 6.02e23 means 6.02 times 10^23. The number after the letter e is the exponent of 10, and a minus sign in front of it means a negative exponent, as in 4.5e-4.
What is engineering notation?
Engineering notation works like scientific notation, except the exponent is always a multiple of 3, which lines up with metric prefixes: kilo (10^3), mega (10^6), micro (10^-6), and so on. For example, 33,000 becomes 33 times 10^3 instead of 3.3 times 10^4.
How do you write zero in scientific notation?
Zero is written as 0 times 10^0. Because zero has no non-zero digit to anchor the decimal shift to, any exponent would work mathematically, so 10^0 is used by convention.
When should I use each format?
They are the same number in different clothes. The times-10-to-the-power form is standard in math and science papers, e-notation fits into spreadsheets, code, and calculator displays, and engineering notation is handy when you think in metric prefixes like milli (10^-3) and giga (10^9).