Scientific Notation Converter
Convert numbers between standard decimal, scientific (a × 10ⁿ), engineering and e-notation. Works both ways — paste any of these forms and get all four back. Handles very large and very small numbers exactly.
Input
Enter a number in standard, scientific (1.5e10 or 1.5×10^10), or grouped (1,500,000) form.
Round the coefficient to this many significant figures, or keep every digit.
Output
Ordinary decimal form with comma thousands grouping.
Coefficient between 1 and 10, times a power of 10.
Like scientific, but the exponent is always a multiple of 3 (kilo, mega, giga…).
Machine-friendly form used in code, CSVs and spreadsheets.
Guides
Convert any number between standard decimal, scientific, engineering and e-notation — in both directions. Paste a plain number, a scientific expression, or an e-notation string, and get all four forms back at once.
What it does
Enter a number in any of these forms and the tool recognises it automatically:
- Standard / grouped:
15000000000or1,500,000,000 - Scientific:
1.5 × 10^10,1.5×10¹⁰(unicode superscript), or1.5×10^-10 - E-notation:
1.5e10,1.5E+10,1.5e-10 - Decimal fractions:
0.0000123
It then renders:
- Standard notation — ordinary decimal form with comma thousands grouping.
- Scientific notation — a coefficient between 1 and 10 multiplied by a power of 10, e.g.
6.022 × 10²³. - Engineering notation — the same idea, but the exponent is always a multiple of 3 so it lines up with SI prefixes (kilo, mega, giga, milli, micro…). The coefficient sits between 1 and 1000, e.g.
602.2 × 10²¹. - E-notation — the machine-friendly form used in code, CSV files and spreadsheets, e.g.
6.022e23.
How to use it
- Type or paste your number into the Number field.
- Optionally choose Significant Figures to round the coefficient — or leave it on Keep all to preserve every digit exactly.
- Copy whichever form you need with the copy button next to each result.
Precision that survives huge and tiny numbers
The converter works on the digits themselves as text, not as a floating-point Number. Ordinary JavaScript loses accuracy past about 16 digits (2⁵³), so a value like 123456789012345678901234567890 would be silently rounded. Here every digit is preserved, whether the number has thirty integer digits or sits far below 0.0000000000000001. Engineering exponents are computed by finding the largest multiple of 3 at or below the number's leading-digit power, including a re-normalisation step so that rounding 999999 up still gives 1 × 10⁶ rather than a malformed 10 × 10⁵.
What is engineering notation used for?
Engineering notation keeps exponents on multiples of 3 because those align with metric prefixes: 10³ = kilo, 10⁶ = mega, 10⁻³ = milli, 10⁻⁶ = micro, and so on. Electrical and mechanical engineers prefer it because a reading of 4.7 × 10³ Ω reads directly as 4.7 kΩ.
How are significant figures counted?
Significant figures are counted from the first non-zero digit of the coefficient. Choosing 3 significant figures turns 45678 into 4.57 × 10⁴. Leading zeros in a fraction (like the zeros in 0.0000123) are never significant, and trailing zeros produced only by rounding are dropped.
Privacy
Everything runs locally in your browser. Your numbers are never uploaded or stored.