How to use this calculator
Project contributions before retirement and withdrawals afterward using a deterministic annual model. The savings-at-retirement figure is the balance when contributions end; subsequent chart points show how retirement spending affects that balance.
Before and after retirement
Before retirement, annual returns apply to the opening balance, then contributions are added at year-end. Employer match is a percentage of your contributions, not your salary. The contribution-increase setting raises your own yearly contribution and the modeled match in later years.
Annual income and monthly Social Security entries are in today’s money. The target income percentage determines desired income, and Social Security reduces the amount withdrawn from savings. Both are assumed to rise with inflation; the model includes inflation during the years before retirement.
Understand shortfall and model limits
During retirement, returns apply before the year-end withdrawal. Withdrawals cannot exceed available funds. Once the account is empty, the model cannot create new returns from money already spent. Monthly shortfall is the largest modeled annual funding gap divided by twelve.
Annual average returns hide market volatility and the sequence of gains and losses. Taxes, benefit eligibility, contribution limits and employer-plan rules are excluded. Actual Social Security adjustments and spending may differ from the shared inflation assumption.
Example: one year of contributions
Start at $10,000, contribute $100 monthly for one year, use a 50% contribution match and assume 0% growth. Savings at retirement become $11,800: $10,000 + $1,200 + $600. If withdrawals then total $6,000 yearly, the account cannot fund two complete retirement years.