Decimal to scientific notation and back, with the normalized form shown alongside the answer.
Scientific notation compresses very large and very small numbers into a tidy mantissa × 10exponent form — the way scientists, engineers, and calculators write quantities like the speed of light (2.998 × 108 m/s) or the mass of an electron (9.109 × 10−31 kg). The two modes below convert an ordinary decimal into normalized scientific notation, and a mantissa-and-exponent pair back into a plain decimal. Every calculation runs in your browser and the working is shown underneath so you can verify it by hand.
Convert an ordinary number into normalized scientific notation
1.234 × 10^3
Tabs across the top: "Decimal → Scientific" turns an ordinary number into mantissa × 10^exponent; "Scientific → Decimal" does the reverse.
In decimal mode, enter one number. In scientific mode, enter the mantissa and the exponent separately. The result updates as you type — there is no submit button.
The big tinted value is the answer, shown with a proper superscript exponent. The mono-spaced line under it spells out the full mantissa × 10^exponent equation.
| Input | Direction | Answer |
|---|---|---|
| 1234 | decimal → scientific | 1.234 × 10^3 |
| 0.00056 | decimal → scientific | 5.6 × 10^−4 |
| −4500 | decimal → scientific | −4.5 × 10^3 |
| 5.6, −4 | scientific → decimal | 0.00056 |
| 6.022, 23 | scientific → decimal | 6.022e+23 |
Keeping the mantissa in [1, 10) gives every number a single canonical form, which makes magnitudes instantly comparable: the exponent alone tells you the order of magnitude, and two numbers can be compared at a glance by their exponents first, mantissas second. It is the convention used throughout maths, physics, and the SI system.
The mantissa is displayed to about six significant figures by default, with trailing zeros trimmed. The raw IEEE 754 double drives the underlying conversion, so the digits shown are exactly what JavaScript would produce for the same operation — nothing is fabricated or rounded beyond the standard's own behaviour.
Authoritative references behind the math, constants, and tables on this page. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.