Genealogy Calculators

Small calculators for the date, age and name questions that come up while researching a family tree.

Tools in this group

• 49 Days After Death Calculator — Enter a date of death and get the Buddhist memorial dates used in Japan: the weekly services to the 49th day, the 100th day and the yearly memorials.
• Age At Death Calculator — Enter a birth date and a death date to get the age in years, months and days, even when the day or month is missing. Or enter a date and an age to get the birth year.
• Ahnentafel Number Calculator — Enter an ahnentafel number to see which ancestor it is, or build the number from your line of fathers and mothers. Load a GEDCOM file to number your own ancestors.
• Hebrew Date Converter — Pick a Gregorian date to get the Hebrew date, or pick a Hebrew date to get the Gregorian one. The page also lists the same Hebrew date in the next years.
• How Many Ancestors Do I Have — Enter your birth year and how many years you assume per generation. You get the number of ancestors in any generation, the running total, a chart and a table.
• Julian to Gregorian Converter — Convert a date from the Julian to the Gregorian calendar or back, with the weekday, the gap in days and the double year used in old English records.
• Soundex Calculator — Paste surnames, one per line, to get four phonetic codes for each and the groups of names that share a code. Or compare two names directly.
• Yahrzeit Calculator — Enter the Gregorian or Hebrew date of death and get the yahrzeit dates for the next years, ready to copy, print or add to your calendar.