Scientific Notation Converter
Convert between decimal, scientific and engineering notation.
The Scientific Notation Converter translates numbers between decimal form, scientific notation (mantissa × 10ⁿ with 1 ≤ mantissa < 10) and engineering notation (exponent a multiple of 3, matching SI prefixes).
Scientists and engineers use these forms constantly because they tame huge and tiny numbers: the speed of light is 3 × 10⁸ m/s, a proton's mass is 1.67 × 10⁻²⁷ kg, and Avogadro's number is 6.022 × 10²³. E-notation (1.5e-3) is how programming languages and calculators write them.
The converter works both ways — type a decimal or a scientific expression and get every form, with the engineering exponent snapped to multiples of three so it lines up with kilo, mega, milli and micro prefixes. Runs locally.
Scientific notation
3.450000 × 10^-6
decimal exponent 3.450000e-6
Engineering notation
3.450000 × 10^-6
exponent a multiple of 3
Accepts 3.45e-6, 1.5E3, or plain 0.000012
Decimal form
0.0015
Mantissa × 10ⁿ
1.500000 × 10^-3
e-notation: 1.500000e-3
Scientific notation writes numbers as mantissa × 10ⁿ where 1 ≤ |mantissa| < 10; engineering notation forces n to a multiple of 3 to match SI prefixes (k, M, G, m, µ…).
How to use the Scientific Notation Converter
- Type a decimal number (like 0.00000345) in the first box.
- Read the scientific and engineering forms.
- Or type an E-notation expression (like 3.45e-6) in the second box.
- Read the full decimal form.
- Copy whichever representation your work needs.
Frequently asked questions
What is the difference between scientific and engineering notation?
Scientific notation requires 1 ≤ mantissa < 10 — 3.45 × 10⁻⁶. Engineering notation forces the exponent to a multiple of 3 — 3.45 µ (345 × 10⁻⁸ → 3.45 × 10⁻⁶), so it matches SI prefixes like k, M, G, m, µ and n.
What does E-notation mean?
The 'e' stands for exponent: 1.5e-3 means 1.5 × 10⁻³ = 0.0015. It is how calculators, spreadsheets and programming languages print very large or small numbers.
Why use scientific notation at all?
It makes magnitudes obvious and arithmetic sane for extreme values — comparing 3×10⁸ to 3×10⁷ is instant, and multiplying adds exponents instead of counting zeros.
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