Numbering Your Family Tree

Common Numbering Systems Used in Genealogy

Example of Register Numbering System, Genealogy, NEHGS
Example of Register Numbering System, "Descendants of John Bailey," New England Historical and Genealogical Register, 1907. NEHGS

Have you ever been elated at the discovery of a compiled family history for your ancestors, only to find yourself confused by all of the numbers and what they mean? Family lineages presented in text, rather than in graphical format, require an organizational system to allow the user to easily follow lines down through descendants or back toward the original ancestors. These standard numbering systems are used to show relationships between generations in a family tree.

In other words, who is connected to whom.

When numbering your genealogy, it is best to adopt a well-established system that is easily interpreted. Even if you're using a genealogy software program to compile your family history, it is still important to understand the differences and formats of the most widely-used numbering systems. If you plan to publish your family history, genealogical quarterlies, magazines and other publications may require a specific format. Or a friend may send you a pedigree chart which uses one of these numbering systems. It isn't necessarily important to learn the ins and outs of every numbering system, but it helps to have at least a general understanding.

Common Genealogical Numbering Systems

While genealogy numbering systems vary in their organization, they all have in common the practice of identifying individuals and their relationships through a specific numbering sequence.

Most numbering systems are used to display descendants of a given ancestor, while one, the ahnentafel, is used to display the ancestors of an individual.

  • Ahnentafel - From a German word meaning "ancestor table," an ahnentafel is an ancestor based numbering system. Good for presenting a lot of information in a compact format, and the most popular numbering system for ascending genealogies.
  • Register Numbering System - Based on the numbering system used by the New England Historical and Genealogical Register, the register system is one of several options for numbering descendant reports.
  • NGSQ Numbering System - Sometimes referred to as the Modified Register System from which it was adapted and modernized, this popular descendant numbering system is used in the National Genealogical Society Quarterly and in many other family history publications.
  • Henry Numbering System - Yet another descendant numbering system, the Henry System is named after Reginald Buchanan Henry, who used it in his "Genealogies of the Families of the Presidents." published in 1935. This system is less often used than the Register and NGSQ systems, and is not accepted for certification projects or by most genealogical publications.