Arithmetic Sequence Calculator

Use our free arithmetic sequence calculator to find the nth term aₙ, common difference d, determine n from aₙ, and generate the sequence — all with step-by-step breakdown.

Math

Mode

First Term (a₁)

Common Difference (d)

Position (n)

nth Term (aₙ)

Formula

An arithmetic sequence is a sequence of numbers where each term differs from the previous by a constant value d (the common difference).

aₙ = a₁ + (n − 1) × d

Percentage: The percentage value you want to apply

Number: The original number or value

Result: The calculated result

How It Works

1Select a mode.
2To find aₙ: enter a₁, d, n.
3To find d: enter a₁, aₙ, n.
4To find n: enter a₁, d, aₙ.
5Click Calculate.

Examples

a₁=3, d=2, n=10

1.a₁₀ = 3 + 9×2 = 21
2.Sequence: 3,5,7,9,11,13,15,17,19,21

Result: 21

Find d given a₁=3, a₁₀=21, n=10

1.d = (21-3)/(10-1) = 18/9 = 2

Result: 2

Find n given a₁=3, d=2, aₙ=21

1.n = (21-3)/2 + 1 = 10

Result: 10

Frequently Asked Questions

A sequence where each term differs by a constant d.

aₙ = a₁ + (n-1)d.

The sequence decreases.

The common difference.

Yes, a₁, d, and terms can be decimals.

Related Calculators

Arithmetic Series Calculator Geometric Sequence Calculator Geometric Series Calculator Mean Calculator Percentage Calculator Basic Calculator

CalculateMe Team

Last updated: 2026-07-14

Arithmetic Sequence Calculator

Formula

How It Works

Examples

a₁=3, d=2, n=10

Find d given a₁=3, a₁₀=21, n=10

Find n given a₁=3, d=2, aₙ=21

Frequently Asked Questions

What is an arithmetic sequence?

What is the nth term formula?

What if d is negative?

What is d called?

Can I use decimals?

Related Calculators

Arithmetic Sequence Calculator

Formula

How It Works

Examples

a₁=3, d=2, n=10

Find d given a₁=3, a₁₀=21, n=10

Find n given a₁=3, d=2, aₙ=21

Frequently Asked Questions

What is an arithmetic sequence?

What is the nth term formula?

What if d is negative?

What is d called?

Can I use decimals?

Related Calculators