Find the missing number in a sequence. Enter numbers with a ? for the missing value.
Missing Number Finder
Academics
Inputs
How useful was this tool?
Type the sequence separated by commas.
Replace the missing number with ?.
Click Calculate — it will detect arithmetic or geometric patterns.
This tool detects arithmetic sequences (adding a fixed number) and geometric sequences (multiplying by a fixed ratio) to find the missing value.
A sequence where you add the same number each time, e.g. 3, 6, 9, 12 (adding 3).