Fibonacci Calculator

Generate Fibonacci sequence or find the nth Fibonacci number. See how each term is calculated.

Generate first Fibonacci numbers

What is the Fibonacci Sequence?

The Fibonacci sequence starts with 1, 1, and each subsequent number is the sum of the two preceding ones: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ...

Formula

F(n) = F(n-1) + F(n-2), where F(1) = F(2) = 1

Golden Ratio

The ratio of consecutive Fibonacci numbers approaches the Golden Ratio (φ ≈ 1.618034).