Fibonacci Sequence Calculator

Use our free Fibonacci sequence calculator to generate Fibonacci numbers with custom initial values (F₀, F₁), view the sequence, and compute the sum of the first n terms.

Math

Mode

Number of Terms (n)

F₀ (First Term)

F₁ (Second Term)

Formula

Generate a Fibonacci-like sequence with any starting values. The standard Fibonacci sequence uses F₀=0, F₁=1. Each term is the sum of the two preceding terms.

Fₙ = Fₙ₋₁ + Fₙ₋₂, with configurable F₀, F₁

Percentage: The percentage value you want to apply

Number: The original number or value

Result: The calculated result

How It Works

1Select generate or sum mode.
2Enter the number of terms.
3Optionally customize F₀ and F₁ (default: 0, 1).
4Click Calculate.

Examples

Standard: F₀=0, F₁=1, n=10

1.0, 1, 1, 2, 3, 5, 8, 13, 21, 34

Result: 34

Sum of first 10 standard

1.0+1+1+2+3+5+8+13+21+34 = 88

Result: 88

Custom F₀=2, F₁=3, n=8

1.2, 3, 5, 8, 13, 21, 34, 55

Result: 55

Frequently Asked Questions

Each term is the sum of the two preceding terms.

F₀=0, F₁=1 (OEIS A000045).

Yes, any initial values produce a Fibonacci-like sequence.

The ratio Fₙ/Fₙ₋₁ approaches φ ≈ 1.618.

Sum of first n Fibonacci numbers = Fₙ₊₂ − F₁.

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CalculateMe Team

Last updated: 2026-07-14

Fibonacci Sequence Calculator

Formula

How It Works

Examples

Standard: F₀=0, F₁=1, n=10

Sum of first 10 standard

Custom F₀=2, F₁=3, n=8

Frequently Asked Questions

What is the Fibonacci sequence?

Standard starting values?

Can I use custom starts?

Golden ratio?

Sum formula?

Related Calculators

Fibonacci Sequence Calculator

Formula

How It Works

Examples

Standard: F₀=0, F₁=1, n=10

Sum of first 10 standard

Custom F₀=2, F₁=3, n=8

Frequently Asked Questions

What is the Fibonacci sequence?

Standard starting values?

Can I use custom starts?

Golden ratio?

Sum formula?

Related Calculators