Scientific Notation Calculator
Convert any number to scientific, engineering, and E-notation — and back again.
Scientific notation writes a number as a value between 1 and 10 times a power of ten. 12,345 becomes 1.2345 × 10^4, and 0.00042 becomes 4.2 × 10^-4. Engineering notation keeps the exponent a multiple of three (12.345 × 10^3), and E-notation writes the same thing as 1.2345e4. Enter a number to convert it, or paste an E-notation value to turn it back into a plain number.
Results are estimates provided for general information.
Decimals and negatives are fine — try 0.00042 or 299792458.
Scientific notation
4.2 x 10^4
- E-notation
- 4.2e4
- Engineering notation
- 42 x 10^3
- Expanded form
- 42000
- Significant figures
- 2
Significant figures are read from the number itself — trailing zeros in a whole number (like 1200) can't be counted as measured, so 1200 reports 2.
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About the Scientific Notation Calculator
Scientific notation is a compact way to write numbers that are very large or very small without a string of zeros. The rule is simple: rewrite the number as a single non-zero digit, then a decimal, then a power of ten that says how far the decimal point moved. So 12,345 is 1.2345 × 10^4 (the point moved four places left) and 0.00042 is 4.2 × 10^-4 (four places right, hence the negative exponent). Engineering notation is a close cousin used in electronics and science: it forces the exponent to be a multiple of three so the powers line up with kilo, mega, milli, and micro, which turns 12,345 into 12.345 × 10^3. E-notation is what calculators and code use — the same 1.2345 × 10^4 shows up as 1.2345e4. This tool converts a number into all three forms at once and also shows the expanded (written-out) value and the count of significant figures. It works in reverse too: paste something like 6.02e23 and it returns the plain number. One honest limit — the significant-figure count comes from the digits you actually type, so trailing zeros that were never entered can't be inferred.
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 ten raised to the number of places you moved. Left moves give a positive exponent, right moves give a negative one. 5,000 becomes 5 × 10^3; 0.007 becomes 7 × 10^-3.
What is the difference between scientific and engineering notation?+
Both use a power of ten, but engineering notation restricts the exponent to multiples of three so it maps onto metric prefixes (10^3 = kilo, 10^6 = mega, 10^-3 = milli). That's why 12,345 is 1.2345 × 10^4 in scientific but 12.345 × 10^3 in engineering notation.
What does the 'e' mean in a number like 1.5e6?+
The 'e' is shorthand for '× 10 to the power of'. So 1.5e6 means 1.5 × 10^6, which is 1,500,000. It's how calculators, spreadsheets, and programming languages display scientific notation. Paste one here and this tool converts it back to a plain number.
How do you handle negative numbers and zero?+
The sign stays out front: -5,000 becomes -5 × 10^3. Zero is a special case — it's written as 0 × 10^0, since there's no non-zero leading digit to normalize.
What are significant figures?+
Significant figures are the digits that carry real information about a measurement's precision. This tool counts the significant digits in the number you enter, which is useful for reporting results to the correct precision in science classes and labs.
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