Fibonacci Calculator

Fibonacci calculator finds the arbitrary terms of the Fibonacci sequence.

Clear
F(14)377zero-indexed, so F(0) = 0
Sum of all terms986equals F(n+2) − 1
Ratio to the previous term1.618025751073approaches φ = 1.61803398875
Golden ratio φ1.61803398875
Binet check377the closed form for F(n)

Terms

nTerm
00
11
21
32
43
55
68
713
821
934
1055
1189
12144
13233
14377

The formula

F(n) = F(n−1) + F(n−2), starting 0, 1

The ratio converges on φ

Divide any Fibonacci number by the one before and the answer approaches the golden ratio (1 + √5)/2 ≈ 1.618034, alternating above and below it. Binet’s formula gives F(n) in closed form from φ alone — remarkable for a sequence defined purely by addition.