Number Sequence Calculator

Identify and generate arithmetic, geometric, and other number sequences.

Result

Fill in the fields above, then press Calculate.

A number sequence calculator identifies the pattern in a series of numbers and predicts the next terms in the sequence.

Enter a comma-separated sequence of numbers and how many next terms to predict. The calculator identifies whether the sequence is arithmetic, geometric, or quadratic, and predicts the next terms.

Examples

Arithmetic

2, 5, 8, 11: d = 3, next terms: 14, 17, 20, 23, 26

Geometric

3, 9, 27, 81: r = 3, next terms: 243, 729, 2187

Quadratic

1, 4, 9, 16: (perfect squares), next: 25, 36, 49

Frequently Asked Questions

How are arithmetic sequences identified?
A sequence is arithmetic if the difference between consecutive terms is constant. For example, 5, 10, 15, 20 has a constant difference of 5.
How are geometric sequences identified?
A sequence is geometric if the ratio between consecutive terms is constant. For example, 2, 6, 18, 54 has a constant ratio of 3.
What if the pattern is not obvious?
The calculator checks for constant first differences (arithmetic), constant ratios (geometric), and constant second differences (quadratic). If none match, it uses the last difference as an estimate.
Related Calculators
Exponent Calculator
Random Number Generator
Permutation & Combination Calculator
Probability Calculator

Quick Tips

  • •Double-check your inputs — small errors lead to incorrect results.
  • •Enter at least 3 terms for more reliable pattern detection.
  • •Use commas to separate values and avoid extra spaces or non-numeric characters.