Scientific Notation Converter
Convert a number between plain decimal, scientific notation, E notation and engineering notation, all at once. Input is accepted in any of those forms — 0.000521, 5.21e-4, or 5.21 × 10^-4 all mean the same thing here. The conversion works on the digits you typed rather than passing them through a floating-point number first, which matters because round-tripping a value with more than seventeen significant digits through a standard numeric type quietly loses the ones you can see on screen. Alongside the four forms you get the coefficient, the exponent, the significant figure count, the matching SI prefix from the engineering form, and a plain-English reading of which way the decimal point moves and how far.
How it works
Type a number in any form — a plain decimal like 0.000521, E notation like 5.21e-4, or written out as 5.21 × 10^-4 — and it is converted to all the others at once.
The conversion works on the digits you typed rather than passing them through a floating-point number first, so a value with more than 17 significant digits keeps every one of them instead of being rounded on the way through.
Every form of the same number
Breakdown
How to read it
Scientific notation is a coefficient between 1 and 10, times a power of ten.
5.21 × 10^-4 means: take 5.21 and move the decimal point 4 places to the left, which gives 0.000521.
Frequently asked questions
What is the difference between scientific and engineering notation?
Scientific notation puts exactly one digit before the decimal point. Engineering notation forces the exponent to a multiple of three so it lines up with the SI prefixes — kilo, mega, milli, micro and so on.
What input formats are accepted?
Plain decimals, E notation like 5.21e-4, and the written form 5.21 × 10^-4 — with ×, x or * as the multiplication sign.
Why does it warn about 64-bit floats?
Because a standard numeric type holds about seventeen significant digits. If you enter more than that, the digits shown here are exactly what you typed, but code that reads the value as a double will round it.
How do I control the number of decimal places?
The decimals selector fixes the coefficient to a set number of places. Leave it on the default and every significant digit is kept.
What does a negative exponent mean?
That the number is smaller than one — the decimal point moves that many places to the left. 5.21 × 10^-4 is 0.000521.
Is this the same as standard form?
Yes. Standard form is the British name for scientific notation; the two are identical.
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