Scientific Notation Converter
Convert numbers between standard decimal form and scientific (and E) notation.
Best for: Use it in science and engineering to handle very large or very small numbers, to match significant figures, or to read the E-notation (like 4.2e-4) from a calculator or spreadsheet.
Purpose: Convert numbers between standard decimal form and scientific (and E) notation.
Input
Result
ExactScientific notation
4.2000 × 10^-4
What to do next
Next: Scientific CalculatorMore about this result
- Type
- Exact Formula
- Method
- Standard mathematical formula
- Confidence
- High
A precise, deterministic calculation - the same inputs always give exactly this result.
The exponent tells you the scale: a positive exponent is a large number, a negative one is a fraction below 1. The mantissa carries the significant figures.
- Watch units and rounding — they change the answer.
- Order of operations matters; group terms carefully.
- Re-run with different inputs to sanity-check the result.
The same data can tell different stories - which average you use changes the answer.
How it's calculated & sources
Free & no sign-up · runs entirely in your browser. Results are estimates for general information, not professional advice — verify important decisions with a qualified expert. Last reviewed June 2026.
How it works
Scientific notation writes a number as m × 10e, where the mantissa m satisfies 1 ≤ |m| < 10 and the exponent e is how many places the decimal point moves.
Example
0.00042 = 4.2 × 10−4 · 93,000,000 = 9.3 × 107
Frequently asked questions
What counts as proper scientific notation?+
The mantissa must be at least 1 and less than 10 (one non-zero digit before the decimal point). 42 × 10^3 is not standard form; 4.2 × 10^4 is.
What does the exponent's sign mean?+
A positive exponent means a large number (move the point right); a negative exponent means a small number below 1 (move the point left).
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