Scientific Notation Converter: Quick and Simple

Convert between decimal and scientific notation instantly. Type in either field to see the conversion.

How to Use:

  • Enter a number in either the decimal or scientific notation field
  • The conversion happens automatically as you type
  • Scientific notation format: mantissa × 10^exponent (e.g., 1.5e+3 = 1500)
  • Use the Copy button to copy the result to your clipboard

Examples:

  • 0.00045 → 4.5e-4
  • 3,500,000 → 3.5e+6
  • -0.0000123 → -1.23e-5

Worked example: a small decimal

Type 0.00045 into the decimal field. The tool calls JavaScript's toExponential(10) on the number, producing 4.5000000000e-4, then strips the trailing zeros to give a clean 4.5e-4. To verify by hand: 4.5 × 10⁻⁴ = 4.5 ÷ 10,000 = 0.00045 — moving the decimal point 4 places left from 4.5 to reconstruct the original number.

Worked example: a large number

Type 3500000 into the decimal field and the scientific field updates to 3.5e+6. Checking it: 3.5 × 10⁶ = 3.5 × 1,000,000 = 3,500,000. The exponent (6) equals the number of places the decimal point moved to get the mantissa (3.5) between 1 and 10.

The two fields are linked, not sequential

There's no Convert button — the tool listens for input in either field and updates the other live. Typing directly into the scientific field, e.g. 2.5e5, fills in the decimal field with 250000 (2.5 × 100,000 = 250,000). For very large exponents (roughly 1e21 and above), JavaScript's own number formatting switches back to exponential notation regardless, since expanding it as plain digits would exceed the precision the format can represent reliably — so extremely large or small scientific values may echo back close to their original form rather than a fully expanded string.

Constraints

Commas in the decimal field are stripped automatically before parsing, so "3,500,000" and "3500000" both work. Text that isn't a valid number in either field produces an inline message rather than a silent failure.