"I want to retire with $1 million" — most people carry a vague number with no idea where it came from, and no idea how much to save each month to get there. Retirement planning isn't fortune-telling. Use the backward method: four steps from a fuzzy goal to a concrete monthly action.
Step 1: Set Your Goal — Monthly Cost in Retirement
First answer: what lifestyle do you want after retiring, priced in today's dollars?
- Basic: $1,500-2,500/month (daily needs, after Social Security/pension)
- Comfortable: $3,000-4,500/month (travel, buffer)
- Premium: $6,000+/month (high-end healthcare, frequent travel)
Social security or a pension covers only part of it. The gap is what you must fund yourself. Example: target $3,000/month, pension gives $1,200 → gap of $1,800/month.
Step 2: Total the Need at Retirement
Estimate a 30-year retirement:
Total needed ≈ monthly gap × 12 × years in retirement
At $1,800 gap × 12 × 30 = $648,000.
That ignores inflation. At 3% yearly inflation, the real requirement is higher — run it in the retirement calculator which models inflation.
Step 3: Project Your Existing Savings
Your current savings, investments, and pension will compound before retirement. Suppose you have $50,000 today, 20 years until retirement, 6% annual return:
$50,000 × 1.06^20 ≈ $160,000.
That covers part of the total — model it with the compound interest calculator.
Step 4: Reverse-Engineer the Monthly Saving
Total $648,000 − projected savings $160,000 = $488,000 shortfall. Over 20 years, how much monthly?
At 6% annualized on monthly contributions: roughly $1,050/month.
At 8%: roughly $830/month — two extra points of return cuts your monthly burden by over $200. That's why learning to invest early pays off.
What Moves the Number Most
- Return rate: biggest lever — 6% vs 8% changes monthly saving by hundreds
- Inflation: quietly halves purchasing power over 30 years at 3%
- Retirement age: 5 extra years = 5 more years of compounding + 5 fewer years of expenses — a double win
Take Action
- Use the retirement calculator to find your total gap
- Use the compound interest calculator to reverse-engineer monthly saving
- Write "save $X/month" into your budget and treat it like a mortgage payment
Retirement planning isn't a one-time calculation. Review it yearly as income, rates, and goals change. The earlier you start, the more generously time rewards you.