RetireNerd Calculator

Retirement Spending Gap Calculator

See how much of your retirement spending may be covered by Social Security, pensions and other dependable income — and how much your savings may need to provide.

Simple estimate

Find your retirement spending gap

Uses today's dollars
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Enter the lifestyle amount you want to spend each month in today's purchasing power.

Expected monthly retirement income

Use today's-dollar estimates so the comparison stays apples-to-apples.

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$
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Examples: annuity income, rental income you expect to keep, or other recurring income. Do not enter planned portfolio withdrawals here.
Optional planning assumptions
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Used only to show an estimated future-dollar equivalent at retirement.
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Used only for the rough portfolio-size reference.
Monthly spending gap

Enter your spending goal and expected retirement income.

Plain-English guide

Why this number matters

Many retirees do not need their investment portfolio to pay for their entire lifestyle. Social Security, pensions and other dependable income can cover part of the monthly budget. The spending gap is the portion left over after those income sources are counted.

Example

If you want to spend $5,000 per month and expect $3,200 per month from Social Security and a pension, your estimated spending gap is $1,800 per month, or $21,600 per year. That is the amount your savings, part-time work, or another source would need to cover before taxes and other adjustments.

What does the portfolio estimate mean?

The calculator also divides the annual gap by the withdrawal rate you choose. A $20,000 annual gap at a 4% planning rate produces a rough reference of $500,000. This is a planning shortcut — not a guarantee that a particular portfolio will last for retirement.

What this calculator does not include

This simple estimate does not model federal or state taxes, Medicare premiums, investment returns, sequence-of-returns risk, changes in spending over time, Social Security taxation, RMDs, Roth conversions, or survivor scenarios. Those are better handled by a full retirement projection.

Before relying on the result

  • Use realistic retirement spending, not just today's bills.
  • Include health care, travel, home repairs and irregular expenses.
  • Keep income and spending in the same dollar basis.
  • Remember that taxes can make the amount your portfolio must distribute larger than the amount you actually spend.
Want to stress-test the gap?

Model taxes, investment returns, Social Security, RMDs and year-by-year withdrawals together.

Try the Retirement Planner & Modeler →

Educational estimate: This calculator is a simplified planning tool and is not financial, tax, or investment advice. The portfolio-size reference is based only on the withdrawal rate you enter and does not account for market performance, taxes, fees, longevity, or changing expenses.