TTN Finance

Retirement Planning Calculator

How much do you need to retire, and how much should you save each month? Compare your projected savings with the amount needed to fund your retirement spending, accounting for inflation and investment fees.

Free to use · No account required · Calculations run in your browser

Your retirement plan

Choose a planning horizon, not a prediction of life expectancy.
Combine balances intended for retirement, including 401(k), IRA and other investments.
Fixed dollar contribution until retirement. Include employer contributions you expect to receive.
Include housing, healthcare and estimated taxes. Spending keeps pace with inflation.
Social Security or pension estimate starting at retirement; modeled as inflation-adjusted. Set to zero if uncertain.
Nominal effective annual return before fees; an assumption, not a forecast.
May differ as your investment mix changes.
Used to keep results comparable in today’s dollars.
Approximation: subtracts percentage points from annual returns.

Your projection

How to use this retirement calculator

Start with the savings you already have and the amount you expect to contribute each month. Enter when you want to retire and how long the plan should fund your spending. Use your own household budget rather than a fixed percentage of your salary.

Add an estimate of income from Social Security or a pension. You can find a personalized Social Security estimate through SSA’s official benefit calculators. Enter income in today’s dollars. This tool assumes it starts at your selected retirement age and rises with inflation; delayed benefits or a pension without inflation adjustments require a separate cash-flow plan.

The monthly contribution result is the total contribution required under the base assumptions, including any employer contribution. It is not an additional amount on top of the contribution you entered.

How much money do I need to retire?

The target covers the difference between your spending and other retirement income over the selected horizon. For example, $4,000 of monthly spending minus $1,800 of other income leaves $2,200 to fund from savings. With 30 years in retirement and a 0% real return, the target is $792,000 in today’s dollars: $2,200 × 360 months.

If other income covers all spending, the modeled target is zero. That does not create a reserve for emergencies, care costs or a bequest. Add those needs to your plan separately. Extending the horizon or increasing spending raises the funding requirement.

Method and assumptions

The model uses constant effective annual returns, reduced by the fee percentage you enter. Monthly return equals (1 + net annual return)1/12 − 1. Contributions are fixed in nominal dollars and added at each month’s end until retirement; they do not automatically rise with salary or inflation.

Projected savings at retirement are divided by (1 + inflation)years until retirement to show today’s purchasing power. During retirement, the annual real return is (1 + net annual return) ÷ (1 + inflation) − 1. The target is the present value, at retirement and in today’s dollars, of the monthly spending gap paid at the beginning of each month. It allows the balance to reach zero at the end of the selected horizon.

The required contribution solves the same accumulation formula for the monthly contribution. If retirement begins now, no future savings contribution can close an existing shortfall, so the tool reports that you are already at retirement.

Actual returns vary. This deterministic model does not measure the probability of success or capture losses early in retirement, tax rules, benefit eligibility, changing healthcare costs or required minimum distributions. Include an allowance for taxes in spending and test lower returns and a longer horizon. A 401(k) and a Roth IRA can have different after-tax spending value even when their account balances match.

Retirement planning questions

Does this use the 4% withdrawal rule?

No. It calculates a spending-based target using your retirement duration and assumed real return. Neither this estimate nor a fixed withdrawal rule guarantees that savings will last.

Does this calculate Social Security benefits?

No. Enter a benefit estimate from SSA. If benefits start later than retirement, this tool’s constant-income assumption can understate the savings needed for the intervening years.

Can I use it for early retirement?

Yes. Choose an earlier retirement age and a longer planning horizon, then account for income that is not yet available. Benefit timing, healthcare and access to retirement accounts need separate review.

Why does inflation matter?

A future balance can look large while buying less. The headline values use today’s dollars so your savings and spending target are comparable.

Are my figures saved?

The calculator does not save your entries or send them as calculation requests. Resetting or reloading clears the plan. The website’s general cookie policy still applies.

Continue planning

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Primary references

These references explain related concepts; they do not endorse or supply the assumptions in this calculator.

TTN Finance · Educational estimates, not personalized financial advice.