Family Tree Chart Formats Compared: Pedigree vs. Fan vs. Descendancy

Open any genealogy program, click print, and it will ask which chart you want. Pedigree, fan, or descendancy. The names sound like variations on the same thing, but they aren't. Each format answers a different question, and picking the wrong one can turn a clear picture of your family into a knot of lines that hides the very thing you were trying to see. The choice usually becomes obvious once you know what each layout was built to do.

Start With the Question, Not the Chart

Before you open the chart builder, write down what you actually want to know. "Who were my mother's grandparents?" is a question about one line going back. "Who else descends from the family that settled in southern Ohio?" is a question about many branches going forward. "How solid is my research on my father's side?" is a question about coverage and gaps. Charts are tools for answering questions, and they rarely answer more than one kind at a time.

Pedigree Charts: The Straight Line Back

A pedigree chart puts one person at the left edge of the page and branches to the right: two parents, four grandparents, eight great-grandparents, and onward. Each generation doubles, which is why the layout feels natural for the first four generations and increasingly crowded after that.

This is the format to use when your goal is proving a direct line. Because every box represents one person in your ancestry, blanks are easy to spot and easy to treat as a to-do list. A pedigree chart full of empty slots is honest about the state of your research in a way that a decorative tree rarely is.

The limitation is breadth. Siblings, aunts, uncles, and cousins never appear. Neither do second marriages or the step-relations and in-laws whose records often hold the answer you need. A pedigree chart shows you the trunk of the tree and nothing else.

A quick word on numbering

Pedigree charts usually carry Ahnentafel numbers: you are 1, your father is 2, your mother is 3, and every father is double his child's number while every mother is one more than that. The system travels well. Writing "I'm trying to confirm Ahnentafel 46" in a message to a fellow researcher is far more precise than describing a great-great-grandmother by name alone.

Fan Charts: The Same Ancestors, Folded Into a Circle

A fan chart takes the same ancestor data and arranges it in concentric rings. The root person sits at the center, parents in the first ring, grandparents in the second, and so on. That packs six or seven generations into a space where a pedigree chart would fit four.

The density is the point. Missing ancestors show up as empty wedges, so a fan chart works like a progress report you can read at a glance. Print one and pin it above your desk; the blank arcs will tell you where to look next. Many programs also color the rings by country, surname, or family line, which turns the chart into a portrait of migration and naming patterns.

The trade-off is legibility. Fonts shrink toward the middle, and long names in the inner rings get cramped. Fan charts also show direct ancestors only, so they carry the same blind spot as a pedigree chart.

Descendancy Charts: Following a Family Forward

A descendancy chart runs the other way. You choose a founding couple—say, your great-great-grandparents—and follow their children, grandchildren, and great-grandchildren toward the present. The output looks like an indented outline, a numbered list, or a top-down tree.

This format earns its keep in several situations:

• Finding living cousins, and confirming that the ones you find actually connect to your line.
• Planning a reunion or a family history book that needs to include everyone, not just the direct line.
• Breaking through a brick wall. Siblings, spouses, and neighbors of your ancestor often left records your direct line never did.
• Sorting DNA matches, since a descendancy chart shows where a match plausibly fits and where it can't.
• Tracking a surname as it spread across counties and states.

Watch the scale. Two parents with six children apiece can produce a chart hundreds of pages long within five generations, so most researchers limit the number of generations or restrict the chart to a single surname at a time.

Comparing the Three Formats

• Pedigree: direction backward; direct ancestors only; best for documenting and auditing one line; grows wide fast.
• Fan: direction backward; direct ancestors only; best for spotting gaps and for display; text gets tight near the center.
• Descendancy: direction forward; all descendants; best for cousins, reunions, brick walls, and DNA work; grows enormous quickly.

Pick the chart that makes your next task visible, not the one that looks best on the wall.

Read that list against your own to-do list. If you're trying to push one line back another generation, a pedigree chart keeps you focused. If you're stuck and suspect the answer sits with a sibling, a descendancy chart is the better lens. If you need to show a relative what you've found, a fan chart printed large is the one people actually stop and study.

A Sensible Way to Use All Three

Most researchers end up using all three rather than choosing one forever. A workable rhythm:

1. Keep a pedigree chart for each of your four grandparent lines, and update it as you confirm each generation.
2. Print one fan chart per line every year or so. The empty rings show you what changed and what stalled.
3. Build descendancy charts only where you need them—a brick wall, a reunion, a cluster of DNA matches—and cap the generations.
4. Before sharing any chart publicly, check what you're revealing about living relatives. Names, birth dates, and addresses of living people deserve care, and a quick check with family members is never wasted effort.

Chart formats are vantage points, not verdicts. Choose the one that matches the question in front of you today, and let it change as your research does.

Photo: kemence99 / Pixabay