A monthly comparison
Let G represent the monthly income goal you enter and E the total of your estimated monthly income sources. The calculator reports max(0, G − E) as its estimated monthly gap. When expected income exceeds the goal, it reports a zero gap and shows the difference as an estimated monthly surplus.
For example, a $4,500 goal and $3,300 of expected monthly income produces a $1,200 monthly gap. Multiplying by 12 gives an annualized gap of $14,400. That arithmetic describes one year at the current monthly difference. It does not mean you need exactly $14,400 in savings, and it does not calculate how much a portfolio must hold for retirement.
A surplus is not a promise
An estimated surplus means the income total you entered is larger than the goal you entered. It is not proof that your plan is secure. The comparison may omit taxes, debt, irregular costs, health-care premiums and services, benefit changes, inflation, longevity, and investment variability. Recheck the figures and make sure both sides refer to the same person or household and the same tax and dollar basis.
Similarly, a shortfall is not a prediction that you will run out of money. It is a signal to review the inputs and consider what scenarios you want to explore.
Household and timing details matter
For a household estimate, enter the combined goal and the income expected to support that household. Consider what might happen if one income stops, a survivor benefit changes, a spouse retires later, or a pension has a different payment option. This calculator does not model those events automatically. You can change inputs and compare separate scenarios, but a new retirement age does not automatically update a Social Security or pension estimate.
Use an official, personalized benefit estimate when available. The SSA benefit estimate page explains how to view estimates based on your earnings record and selected claiming timing.
What to do with the number
Check the monthly inputs, compare them against a budget and benefit statements, and run a second scenario when an assumption changes. If the estimate is a shortfall, the shortfall guide describes general topics to review. If it is a surplus, review costs and uncertain assumptions before drawing conclusions.
Read the complete methodology and use the worked examples to see the difference between a goal, expected income, a gap, and a surplus.
Related pages
Review the calculator methodology, compare hypothetical worked examples, or return to the free retirement income calculator.