Genealogy & Family
Ancestor count calculator
How many ancestors you have at the Nth generation (2ⁿ).
- Instant
- Free
- Private (processed locally)
- No sign-up
Count your ancestors
Enter the number of generations: the tool gives the ancestors at that generation (2ⁿ) and the running total (2^(n+1) − 2), with a per-generation table.
The doubling
- n=1: 2 parents
- n=2: 4 grandparents
- n=3: 8 great-grandparents
- n=10: 1,024 ancestors
Example
| Generation | Ancestors | Total |
|---|---|---|
| 5 | 32 | 62 |
| 10 | 1,024 | 2,046 |
| 20 | 1,048,576 | 2,097,150 |
Theoretical value (no pedigree collapse). 100% local calculation.
Frequently asked questions
How many ancestors at generation n?
2ⁿ: 2 parents (n=1), 4 grandparents (n=2), 8 (n=3)… At n=10, already 1,024 ancestors.
And the running total?
The sum up to generation n is 2^(n+1) − 2. For n=10: 2,046 ancestors in total.
Is it realistic?
Not beyond a few centuries: due to pedigree collapse (shared ancestors), the real number of distinct people is far smaller.
What is it for?
To grasp the scale of a family tree and estimate the research effort per generation.