Life Expectancy & Longevity Planning Calculator

Life expectancy is a median — it's the age by which about half of people your age will have died, which means the other half live longer, sometimes much longer. Planning your money to run out at your life expectancy gives you roughly a coin-flip chance of outliving your savings. That's why planners budget to a later age, often the age only 25% or 10% of people reach. Building in that buffer is longevity insurance for the scenario that actually hurts: living longer than average with the money already gone.

For a couple, what matters for planning is how long at least one of you is likely to be alive, because your spending and your survivor's needs continue until the second death. The calculator combines each person's individual survival odds from the SSA life table into a joint “last survivor” probability — the chance that either spouse is still living at each future age. Because two people have two chances to reach old age, the joint plan-to age is meaningfully higher than either person's alone, which is why married couples should budget for a longer horizon.

It uses the U.S. Social Security Administration's period life table — specifically the 2023 table used in the 2026 Trustees Report — which gives the probability of dying within one year at each age for males and females. These are population-wide averages. The health adjustment applies a simple multiplier to those mortality rates to reflect better- or worse-than-average health, but it can't account for your specific medical history, family longevity, or lifestyle, so treat the result as a planning estimate rather than a personal prediction.

Claiming age is essentially a bet on longevity. Delaying Social Security raises your monthly benefit about 8% per year of delay up to age 70, and the longer you live, the more that larger check pays off. If your plan-to age is in your late 80s or 90s — which is common, especially for couples and women — delaying tends to win, and the higher benefit also becomes the survivor benefit for a spouse. If your realistic longevity is short due to health, claiming earlier can make more sense.

It's a reason to plan, not to worry. A long life is a good outcome; the risk is only that the money doesn't last as long as you do. The fixes are well understood: budget to a conservative plan-to age, consider delaying Social Security to lock in a larger inflation-adjusted lifetime benefit, keep a sensible withdrawal rate, and for some retirees, use an annuity to guarantee income you can't outlive. Knowing your realistic horizon is the first step to making those choices deliberately.