What a pedigree chart is
A pedigree chart, also called an ancestor chart, shows one person and their direct ancestors: two parents, four grandparents, eight great-grandparents, sixteen 2nd great-grandparents and so on. It reads from left to right. The person the chart is about sits on the left, and each generation further back takes one column to the right, with every person’s father above and mother below.
Genealogists use pedigree charts as a map of their research. Because the shape is fixed, an empty box is a question waiting for an answer, and you can see at a glance which lines you have traced and which have stalled. The layout above follows the printed forms long used by genealogical societies and FamilySearch: numbered boxes, lines for birth (b.), place (p.), marriage (m.) and death (d.), a chart number, and a footer for who prepared it.
How to use this chart maker
- Choose 4, 5 or 6 generations. Four generations fit comfortably on Letter or A4 with room for full details; six generations use a compact one-line box for the outer column.
- Click box 1 and enter the person the chart is about. Use the person list or the Father, Mother and Child buttons to move around.
- Write dates the way the record gives them (“12 Mar 1890”, “abt. 1850”, “bef. 1720”). Write places from smallest to largest: town, county, state or country.
- Choose Download PDF, or open the menu beside it to print or save a PNG. “Download blank PDF” and “Print blank chart” give you a clean form to take to an archive or a relative’s kitchen table.
How to read Ahnentafel numbers
Ahnentafel is German for “ancestor table”. The system gives every ancestor a unique number, and the arithmetic does the bookkeeping for you: the father of person n is 2n, the mother is 2n + 1, and the child of any ancestor is half their number, rounded down. Men (other than number 1) are always even and women always odd.
| Number | Relationship | Why |
|---|---|---|
| 1 | You (the subject) | Where the chart starts |
| 2, 3 | Father, mother | 2 × 1 and 2 × 1 + 1 |
| 4, 5 | Father’s father, father’s mother | Parents of 2 |
| 6, 7 | Mother’s father, mother’s mother | Parents of 3 |
| 8–15 | Great-grandparents | Generation 4 runs from 2³ to 2⁴ − 1 |
| 10 | Father’s mother’s father | Father of 5 |
| 16–31 | 2nd great-grandparents | Generation 5 |
| 32–63 | 3rd great-grandparents | Generation 6 |
To trace a number back down to you, keep halving: 45 → 22 → 11 → 5 → 2 → 1. Reading those steps as father (even) or mother (odd) gives the line: 45 is your father’s mother’s mother’s father’s mother. The same numbers are used in written “Ahnentafel reports”, so a chart and a report can be cross-referenced without names.
Pedigree chart, family tree or family group sheet?
| Form | Shows | Best for |
|---|---|---|
| Pedigree chart | Direct ancestors only, two per person, a fixed number of generations | Planning research, spotting gaps, sharing a summary |
| Family tree | Anyone: siblings, aunts, uncles, cousins, descendants | Showing the whole family; try the family tree maker |
| Family group sheet | One couple and all their children, with full dates, places and sources | Recording the evidence behind each pair of boxes on the pedigree |
The three work together. Each couple on a pedigree chart usually has its own family group sheet, where the brothers and sisters, the sources and the details that do not fit in a box are written down. You can print a blank family group sheet from our printable family tree templates.
Genetics pedigree symbols
In biology and medical genetics, “pedigree” means something slightly different: a diagram of a family that tracks one trait or condition through the generations. The symbols are standardized (the conventions most textbooks follow were set out by the National Society of Genetic Counselors), and the genetics tab above uses them.
| Symbol | Meaning |
|---|---|
| Male, unaffected | |
| Female, unaffected | |
| Sex unknown or not specified | |
| Affected individual (filled) | |
| Heterozygous carrier of a recessive allele (half-filled, as used in many textbooks) | |
| Carrier not expected to show the condition, e.g. a female carrier of an X-linked trait (dot in the center) | |
| Deceased (diagonal line) | |
| Proband: the affected person through whom the family came to attention (arrow, often with a P) | |
| Consanguineous relationship: partners who are blood relatives (double line) |
A horizontal line joins partners; a vertical line drops from it to a sibship line, and each child hangs from that line in birth order, oldest on the left. Generations are labelled with Roman numerals and individuals with Arabic numerals from left to right, so “III-2” is unambiguous in a lab report. When you analyze a pedigree, look for whether affected individuals appear in every generation (suggesting dominant inheritance), skip generations (recessive), or are mostly males linked through unaffected mothers (X-linked recessive).
How to fill in a pedigree chart from records
- Work backwards from what you know. Fill in yourself, your parents and grandparents first, from your own documents and what living relatives can confirm. Each generation’s records point to the next.
- Use the record that was made at the time. A birth certificate or baptism register is better evidence for a birth date than a death certificate written decades later. Census returns give ages and birthplaces that point you to the right parish or county.
- Write what the record says. Keep dates in day-month-year form with the month as a word (“4 Jun 1886”) so no one confuses 4 June with April 6. Use “abt.”, “bef.” and “aft.” for estimates rather than inventing a precise date.
- Leave doubt visible. If a parent is only probable, use pencil on paper or note it in your research log rather than filling the box as fact. An honest gap is more useful than a wrong name that sends you down someone else’s family line.
- Record your sources on a family group sheet for each couple, so anyone using your chart can check the evidence.