How to Calculate What You Actually Need to Retire
A plain-English method using your pension, 401(k), and Social Security — no jargon, no guessing.
Step 1: Add up your guaranteed monthly income
Start with the money that shows up every month no matter what. This is your foundation.
- ◆Social Security: create an account at ssa.gov to see your estimated monthly benefit at 62, your full retirement age, and 70.
- ◆Pension: ask HR or your plan administrator for your estimated monthly payout and whether it includes a survivor benefit.
- ◆Annuities or rental income: include only what reliably arrives each month.
Step 2: Estimate your real monthly spending
Track three months of spending, then adjust for retirement. Most people spend 70–85% of their pre-retirement income, but healthcare often goes up.
- ◆Housing (or zero if your home is paid off — a huge advantage)
- ◆Healthcare premiums, copays, and prescriptions
- ◆Food, transportation, insurance, and fun
- ◆A line for travel to see kids and grandkids
Step 3: Find your gap, then size your nest egg
Subtract guaranteed income (Step 1) from spending (Step 2). That monthly gap is what your savings must cover.
A safe rule of thumb: multiply the annual gap by 25 (the '4% rule'). If your gap is $1,500/month = $18,000/year, you'd want roughly $450,000 invested. If your guaranteed income already covers your spending, you may need far less.
Step 4: Pressure-test it
Run the numbers again assuming a market downturn early in retirement and a few years of higher medical costs. If the plan still holds, you're in good shape. If not, the levers are: work 1–2 more years, claim Social Security later, trim fixed costs, or relocate somewhere more affordable.