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Retirement Calculator

Project a retirement portfolio under your assumed effective annual return, fixed monthly contributions, and inflation, then compare it with an estimated portfolio target based on desired spending and a withdrawal-rate assumption. Desired spending is entered in today's dollars. The calculator inflates that spending to the retirement date before computing the nominal target. Results are planning illustrations — not guarantees.

Whole years, 18–100.

Must be greater than current age (up to 120).

Fixed nominal amount at the end of each month — not automatically increased with inflation.

Effective annual return assumption — hypothetical, not guaranteed. May be negative (greater than −100%).

Effective annual price-change assumption. Deflation (negative) is allowed above −100%.

Entered in today's dollars. Inflated to the retirement date before calculating the nominal portfolio target.

Illustrative planning assumption you can adjust — not a recommendation or “safe” withdrawal rate.

Your results will appear here

Enter your assumptions and calculate to see the estimated result and supporting details.

How this calculator works

Enter current age, retirement age, current savings, monthly contribution, expected effective annual return, inflation, desired annual spending in today's dollars, and a withdrawal-rate assumption.

The portfolio grows with end-of-month contributions using the effective-annual-return convention. The primary result is the projected retirement portfolio. Secondary results show today's-dollar equivalents, targets, and funding surplus or shortfall under your assumptions.

Formula / methodology

rm = (1 + annualReturn)^(1/12) − 1
portfolio_m = portfolio_(m−1) × (1 + rm) + contribution
futureSpending = spendingToday × (1 + inflation)^years
nominalTarget = futureSpending / withdrawalRate
realTarget = spendingToday / withdrawalRate
realPortfolio = nominalPortfolio / (1 + inflation)^years
realReturn = (1 + nominalReturn) / (1 + inflation) − 1
  • Monthly contributions are fixed nominal amounts and are not automatically increased with inflation.
  • Withdrawal rate is a user-supplied planning assumption — not a recommendation and not a guarantee the portfolio lasts for any particular period.
  • Compare nominal portfolio with nominal target, or today's-dollar portfolio with today's-dollar target — never mix bases.

Worked example

Age 35 → 65, $100,000 current savings, $1,000 monthly, 7% effective return, 2.5% inflation, $60,000 desired spending today, 4% withdrawal assumption.

Projected nominal portfolio ≈ $1,930,678. Today's-dollar portfolio ≈ $920,437. Nominal target ≈ $3,146,351. Under these assumptions the projected portfolio is below the estimated target.

Important assumptions

  • Expected return and inflation are constant effective annual assumptions you supply.
  • Contributions occur at the end of each month and stay fixed in nominal dollars.
  • Desired spending is entered in today's dollars.
  • Withdrawal rate is an adjustable assumption for target arithmetic only.
  • Social Security, pensions, taxes, fees, healthcare, and drawdown simulation are not included.

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