What is the Fibonacci sequence?

The Fibonacci sequence starts with 0 and 1, and each subsequent number is the sum of the two preceding ones: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34...

How large a number can this generate?

This tool uses JavaScript BigInt, which can handle arbitrarily large Fibonacci numbers limited only by your device's memory.

The ratio of consecutive Fibonacci numbers approaches the golden ratio (≈1.6180339887) as n increases.

No, all calculation is done entirely in your browser.

Generate Fibonacci numbers and sequences. Calculate the nth Fibonacci number or generate a sequence up to n terms.

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