Methodology
Your timeline compares chapter dates with a starting point and an as-of date. The original generation chart uses a separate population model, documented below.
Personal timeline
In the default view, a chapter’s percentage is its elapsed calendar days divided by the elapsed days since your starting point, multiplied by 100. If the start is your birthday, that means a share of your life so far. Otherwise, it is a share of the timeline you chose.
Each chapter has its own row. Overlapping chapters can add up to more than 100%, because the same days can belong to a job, a relationship, and a place. An ongoing chapter ends at the as-of date for calculation.
The whole-life perspective uses your chosen horizon instead: elapsed chapter days divided by the calendar days from your start to that anniversary. Planned spans may extend into the future, but the percentage counts only time already lived. Values are rounded to one decimal place and capped at 100%.
Dates are calendar dates, not time-of-day timestamps. Month-only dates are displayed as months and use the first day of that month for calculation. Durations count the days between the start and end, without adding an extra inclusive day. Short duration labels round months, while percentages use actual calendar days.
Live timelines use the viewer’s local date and update while open. A fixed snapshot keeps its selected as-of date. A February 29 horizon falls on February 28 in a non-leap year. If a chosen horizon has passed, the view extends to the as-of date so your lived chapters remain visible. None of these settings estimates when you will die.
Original generation chart
Chetty et al.’s national, race- and ethnicity-adjusted expected age at death at age 40 for the 75th household-income percentile. The model takes an equal arithmetic mean of the published male and female values.
85.0786285 years
SSA 2026 Trustees Report Table V.A5 Intermediate cohort life expectancy at birth. Male and female values are averaged for each birth year, then expressed relative to 1967.
1967 reference: 78.3 years
The model converts the estimated age to days using the mean Gregorian calendar year and subtracts exact UTC calendar days between a birth date and the daily UTC−04:00 as-of date.
365.2425 days per year
Calculation
85.0786285 + [SSA cohort e0(birth year) − 78.3]estimated age at death × 365.2425round(modeled lifetime days − calendar days lived)round(days left ÷ modeled lifetime days × 100)For a 1967 birth year, the cohort-shift bracket is zero, so the estimated age equals the Chetty baseline before elapsed calendar days are subtracted. This is a reference case, not a prediction for every person born in 1967.
Chart construction
The chart uses Boomers (1946–1964), Gen X (1965–1980), Millennials (1981–1996), Gen Z (1997–2012), and Alpha (2013 onward). These match the U.S. Census Bureau’s 2025 birth-cohort bands; Pew provides additional documentation for the Millennial and Gen Z boundary.
Each gold range connects the modeled percentage for the oldest and youngest boundary date. Alpha’s youngest boundary is the as-of date because the cohort is open. The white point uses one stable representative birth date near the center of each band. It is a chart reference, not a population-weighted median.
Read the deeper explanation in life expectancy by generation.
Scope
Illustrative population estimate only. It is not personal, medical, actuarial, insurance, or financial advice.
Primary sources