Retirement Calculator

Start with what you know

How to use this calculator

1. 1
   Enter ages, income, and retirement accounts.

   Household planners can use combined totals. The calculator treats them as one scenario and does not collect person-specific benefit records.

2. 2
   Describe saving and retirement spending in the clearest unit.

   Toggle between dollars and percentages. Spending and other income are interpreted in today’s dollars.

3. 3
   Optionally include other retirement income and inspect assumptions.

   Leave the field at $0 or enter a combined monthly estimate, then open the advanced section to test returns, inflation, growth, and timing.

What your results mean

“On track” means the modeled retirement balance in today’s dollars meets or exceeds the present value of the entered retirement-income gap. A shortfall is not a score or prediction; it is the difference between two transparent scenario values.

The monthly income result spends the projected nest egg down over the entered retirement span using the real return assumption. The 4% row is a separate rule-of-thumb comparison calculated as 4% of projected real savings divided by 12; it is not the engine’s target methodology.

Deterministic model

Retirement methodology

1. Project savings monthly. The annual return is converted to an equivalent monthly rate. Percentage contributions track salary growth; fixed contributions track the contribution-growth assumption. Beginning deposits grow for that month; end deposits do not.
2. Find the income gap in today’s dollars. Desired monthly spending minus the entered other retirement income amount cannot fall below zero.
3. Convert return and inflation into a real rate. The calculator uses ((1 + nominal annual return) / (1 + inflation))^(1/12) - 1.
4. Price the target nest egg. The calculator finds the present value at retirement of a level real monthly income gap through life expectancy. When the real rate is zero, the target is simply monthly gap × number of months.
5. Solve the contribution gap. A bounded bisection search reruns the same savings projection until the ending balance is within $1, or one ten-billionth of the nominal target when larger. The displayed amount is the additional monthly amount to start saving now; it follows salary growth for percentage-based scenarios or contribution growth for fixed-dollar scenarios. The exact solved amount is verified before currency display rounding.

Assumptions and limitations

• The default assumptions are age 67, life expectancy 95, 6% before retirement, 5% in retirement, 3% inflation, 2% salary growth, and a retirement spending goal equal to 70% of current income. They are hypothetical starting points, not forecasts.
• The calculator does not estimate government benefits or request an earnings record. Include a separate monthly estimate only if you want it reflected in the scenario.
• Taxes, investment fees, market volatility, sequence-of-returns risk, changing benefit rules, health and long-term-care costs, and actual lifespan are not modeled.
• Returns and inflation are smooth and constant. Real results vary year to year and may include losses.
• The model does not enforce account-specific 401(k), IRA, Roth IRA, catch-up, or employer-match limits.

Common questions

Frequently asked questions