Check the assumptions behind the result.

Monthly cash-flow equations

All money is in today’s dollars. Enter an effective annual nominal return after taxes and fees, g, and annual inflation, i. The real annual rate is (1 + g) / (1 + i) − 1. The equivalent monthly rate r is (1 + real annual rate)^1/12 − 1. Percent inputs are divided by 100 before calculation.

With initial capital C and monthly withdrawal W, end-of-month balance is B_m = B_m−1(1 + r) − W. At zero return, the number of funded months is floor(C/W). For nonzero return, the depletion boundary is −ln(1 − Cr/W) / ln(1 + r), rounded down to fully funded months. If r is positive and Cr ≥ W, the fixed scenario does not deplete. A zero withdrawal needs no capital; zero capital with positive withdrawals funds no months.

Required starting capital for n months is W[1 − (1 + r)⁻ⁿ]/r, or Wn at zero return. The tools show remaining balance or the additional capital required at a selected horizon. Monthly withdrawals occur after growth; beginning-of-month withdrawals would need more capital. Values are rounded for display only.

Constant returns exclude market volatility and sequence-of-returns risk. These calculations are cash-flow identities, not validated retirement safety models. Return, income, expenses and inflation can change. No tax bracket or withdrawal-tax calculation is performed.

Sleep-pattern check-in

This check-in describes your answers. It does not estimate biological age, a Sleep Regularity Index, disease risk or years of life lost. Adult sleep guidance varies by age; a reported average does not diagnose a sleep disorder.

Source: CDC adult sleep guidance, reviewed October 3, 2026. Bring persistent sleep problems to a qualified clinician.

Plan your household runway

Return is a constant assumption, not a forecast. We convert it to a real monthly rate, apply growth, then withdraw at the end of each month. Spending stays constant in today’s dollars. This omits market volatility, changing income, large one-off expenses and sequence risk. Try lower returns and higher spending as well.

Each planning window is chosen age minus current age. Shared savings are compared with the longer window. This assumes the same household withdrawal throughout; it does not predict either partner’s lifespan or model survivor income and expenses.

Compare two living budgets

Return is a constant assumption, not a forecast. We convert it to a real monthly rate, apply growth, then withdraw at the end of each month. Spending stays constant in today’s dollars. This omits market volatility, changing income, large one-off expenses and sequence risk. Try lower returns and higher spending as well.

The alternative starts with savings minus the moving cost. Both budgets use the same return and inflation. These are your cost assumptions, not researched destination budgets. Include health insurance, travel, visas, exchange-rate changes and taxes when constructing them. A longer financial runway does not imply longer life or access to future treatments.

Savings and your planning horizon

Return is a constant assumption, not a forecast. We convert it to a real monthly rate, apply growth, then withdraw at the end of each month. Spending stays constant in today’s dollars. This omits market volatility, changing income, large one-off expenses and sequence risk. Try lower returns and higher spending as well.

The planning window is your selected age minus current age. Capital required is the present value of that many monthly withdrawals. “No depletion under these fixed assumptions” is not a guarantee of investment safety.

Make room for an active retirement

The activity window begins at the later of your current age and retirement age, and ends at your chosen activity-planning age. It is a personal scheduling assumption, not a prediction of health, disability or lifespan. No age is a universal cutoff for being active.

Compare your planning horizons

Both endpoints are your assumptions. The difference is planned coverage age minus desired coverage age. The tool does not validate your budget, infer health from a score, recommend spending more, or tell you how long you will live. Use the savings calculator to examine the financial assumption.

Plan for a future milestone

Return is a constant assumption, not a forecast. We convert it to a real monthly rate, apply growth, then withdraw at the end of each month. Spending stays constant in today’s dollars. This omits market volatility, changing income, large one-off expenses and sequence risk. Try lower returns and higher spending as well.

The starting year comes from the current calendar year. Your age at the milestone is current age plus elapsed calendar years; birthdays within the year are not modeled. A chosen research milestone date does not predict when a treatment will exist, work or become accessible. There is no survival probability or intervention-tier recommendation.

Compare countries

Values come from the same World Bank snapshot used by the Global Data Atlas (compiled September 16, 2026). Each value shows its observation year; different years are not an exact same-period comparison. GDP per person at purchasing-power parity is measured in current international dollars, not household wealth or an individual salary.

Life expectancy at birth describes a population under mortality conditions for that period. It is not your remaining life expectancy, a moving-country benefit, or evidence that GDP causes a lifespan difference. We do not subtract dollars from years or invent a future convergence score.

Sources: World Bank GDP per person, PPP and male / female life expectancy. CC BY 4.0; indicator terms apply.