Core Pension Rules of Thumb
- 30 years at 2.0% = 60% salary replacement — the baseline for a solid pension career
- Never leave an employer within 6 months of a major vesting or eligibility threshold
- Early retirement at 5+ years before normal retirement age typically requires 20–30% supplemental savings to compensate
- A pension with no COLA needs 25–30% more in savings than a pension with full COLA
- If your employer match is 100% of your first 3–5%, the 401k/457b has a guaranteed 100% return — contribute to that threshold first
- Rule of 80 threshold is usually the best target retirement date in tiered public plans
- Always model survivor benefit cost as a percentage of total monthly income before electing
Common pension rules of thumb, the math behind them, and when they don’t apply
| Rule of Thumb | The Math Behind It | When It Breaks Down |
|---|---|---|
| 30×2% = 60% replacement | 30 years × 2.0% = 60% of salary | Tiered multipliers, benefit caps, COLA differences |
| $1M pension = $40K/year | 4% withdrawal rate rule applied to lifetime value | Doesn’t account for guarantee premium |
| Early retire 5% reduction per year | Typical reduction — varies 3–8% by plan | Actuarial plans may differ significantly |
| Save 15% of gross for retirement | With no pension; reduce to 5–8% with strong pension | Applies less to those with generous pensions |
| COLA-less pension worth 75% of stated value long-term | Inflation erosion over 20-year horizon | Depends heavily on actual inflation rate |
Rules for Supplemental Savings Alongside a Pension
Even with a generous pension, supplemental savings in a 457b or 403b serve critical functions: healthcare costs before Medicare eligibility at 65, COLA gap coverage in inflation, home repairs and emergencies, legacy planning, and flexibility for early retirement bridging. The rule of thumb: target 6–10 times your expected annual savings gap in supplemental savings by retirement. If your pension covers $3,500/month and you need $4,500/month, your $1,000/month gap × 300 months (25 years) = $300,000 in supplemental savings target.
Target total retirement income (pension + Social Security + investment withdrawals) equal to at least 80% of your final working salary. If your pension alone provides 55% and Social Security provides 25%, you are at 80% without any additional savings. If your pension is 40% and Social Security is 20%, you need supplemental income for 20%.
Test These Rules Against Your Real Numbers
Enter your plan details to see your actual replacement rate and whether you’re on track for the 80% rule.