Scientific Notation Converter
Enter a number or scientific notation (e.g. 1.5e3) to convert between the two forms.
Reviewed by the ToolNestr Editorial Team — July 2026
How the scientific notation converter works
Scientific notation is a compact way to write numbers that are very large or very small. Instead of counting long runs of zeros, you express the value as a coefficient between 1 and 10 multiplied by a power of ten. The light from the sun travelling 150 million kilometres becomes 1.5 × 10^8 km; the width of an atom becomes around 1 × 10^-10 m. This converter moves between that standard form and the everyday decimal form in both directions.
Enter a plain number such as 1500 or 0.0042, and the tool finds the power of ten that leaves a coefficient in the range 1 to 10, giving 1.5 × 10^3 or 4.2 × 10^-3. Enter scientific notation — written as 1.5e3, 1.5E3 or 1.5 × 10^3 — and it expands the value back into a full decimal. It also shows the E-notation form used by calculators and programming languages.
Working in scientific notation keeps significant figures clear and makes it easy to compare magnitudes at a glance, which is why it is the standard in physics, chemistry, astronomy and engineering. The conversion runs entirely in your browser, so it is instant and private, and it accepts positive or negative numbers and exponents.
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Frequently asked questions
What is scientific notation?
Scientific notation writes a number as a coefficient between 1 and 10 multiplied by a power of ten, such as 1.5 × 10^3 for 1500. It makes very large and very small numbers compact and easy to compare.
How do I enter scientific notation?
Type it as 1.5e3, 1.5E3, or 1.5 x 10^3. The converter understands these forms and also accepts a plain decimal like 1500 or 0.0042.
How does the conversion work?
To go from a number to standard form, the converter finds the power of ten that leaves a coefficient between 1 and 10. To expand, it multiplies the coefficient by that power of ten.
Why use scientific notation?
It is essential in science and engineering for handling quantities like distances in space or sizes of atoms without writing long strings of zeros, and it keeps significant figures clear.