Scientific Notation Converter
Convert numbers between standard, scientific, engineering, and E-notation forms.
Written by Golam Rabbani, Founder & Lead Engineer
How to use this scientific notation converter
- Pick a conversion direction — Standard → Scientific, Scientific → Standard, or Any → Engineering.
- Type the number into the Number field. The tool accepts plain digits, E-notation (1.23e5), and human-readable forms like 1.23 × 10^5.
- Set the mantissa decimal places (0 to 20) to control how the result is rounded.
- Press Convert to see scientific, engineering, E-notation, and standard form side by side.
- Use each row's Copy button to grab a single form, or Reset to start over.
About this scientific notation converter
The converter parses your input in three ways: a plain number, JavaScript E-notation (`1.23e5`), or human-readable `1.23 × 10^5`. It then renders the value in four forms:
- Scientific notation (single non-zero digit before the decimal). - Engineering notation (exponent is a multiple of 3, matching SI prefixes). - E-notation (the form used in programming languages and spreadsheets). - Standard form (the expanded decimal — useful for visual inspection of very small numbers).
A concrete example: enter Avogadro's number, `602214076000000000000000`, with 4 decimal places of precision.
- Scientific: `6.0221 × 10^23` - Engineering: `602.2141 × 10^21` (exponent locked to a multiple of 3) - E-notation: `6.0221e+23` - Standard: `602214076000000000000000`
Engineering notation is the form electrical engineers and physicists prefer because the exponent matches an SI prefix (kilo = 10^3, mega = 10^6, giga = 10^9, …). All formatting uses JavaScript number arithmetic, which is precise to ~15–17 significant decimal digits. Numbers outside that precision should be entered with enough decimal places to capture the meaningful figures.
FAQ
- What input formats does the converter accept?
- It accepts plain numbers (`1234.56`), E-notation (`1.23e5` or `1.23E-7`), and human-readable scientific notation (`1.23 × 10^5` or `1.23 x 10^5`). Commas are stripped before parsing, so `1,234,567` is also valid.
- What is the difference between scientific and engineering notation?
- Scientific notation always has exactly one non-zero digit before the decimal point. Engineering notation rounds the exponent down to the nearest multiple of 3, so the mantissa may have 1, 2, or 3 digits before the decimal but the exponent always lines up with an SI prefix.
- How precise is the result?
- The converter uses JavaScript's 64-bit floating-point numbers, which are precise to about 15–17 significant decimal digits. For higher precision (cryptographic constants, hashes), use a BigInt-based tool — those values are exact integers and do not need scientific notation.
- Can I convert very small numbers?
- Yes. The tool handles values as small as 10^−308 and as large as 10^308 — the full IEEE 754 double-precision range. Numbers outside that range are reported as "not finite".
- Why does standard form sometimes still show E notation?
- For numbers smaller than 10^−6 or larger than 10^21, the tool expands the digits manually to avoid showing E-notation. Inside that range it relies on `toLocaleString`, which formats them without an exponent.
- Is anything sent to a server?
- No. All parsing and formatting runs locally in your browser; nothing is uploaded or stored.