Pension Lump Sum vs Monthly Annuity Calculator

Lump Sum vs Monthly Annuity: The Big Decision When you retire, many pension plans offer a choice:

• Take a lump sum, a large one-time payment you invest and manage yourself
• Take a monthly annuity, guaranteed income for life (or for a set period)

Neither option is universally better. It depends on your health, investment skills, life expectancy, and family situation.

Lump Sum Invested If you take the lump sum and invest it, your portfolio value at year n: Portfolio value = Lump sum × (1 + r)^n

You control the money but take on investment risk and longevity risk.

Cumulative Monthly Payments Total received after n years = Monthly payment × 12 × n

The monthly annuity is simple and guaranteed, but it does not grow unless the plan is inflation-adjusted.

Break-Even Year The break-even is roughly when cumulative monthly payments equal the lump sum amount. Break-even years ≈ Lump sum / (Monthly × 12)

The comparison that actually matters, and the one most calculators get wrong

Setting an untouched, compounding portfolio beside a stream of pension cheques is not a fair fight, and it flatters the lump sum enormously. The retiree in that scenario let the portfolio grow for twenty-five years and lived on what, exactly? If you take the lump sum, you have to draw an income from it, and that changes the answer completely.

So this calculator runs a third figure: the lump sum invested at your return rate while you withdraw the same amount the annuity would have paid. That tells you how long the money lasts. In the example below the untouched portfolio looks like a landslide win, while the drawdown scenario runs dry after 23 years and the annuity carries on paying for as long as you live.

Worked Example Lump sum: $250,000 | Monthly payment: $1,500 | Investment return: 5%

Simple break-even (no investment): $250,000 / ($1,500 × 12) = 13.9 years At 20 years: cumulative payments = $360,000 against an untouched portfolio of about $663,000 At 30 years: cumulative payments = $540,000 against an untouched portfolio of about $1,081,000 Drawing $1,500 a month from that same $250,000 at 5%: the account empties after about 279 months, so 23 years and 3 months

Key Considerations

• Health: if you expect to live well past 80, the annuity often wins long-term
• Inheritance: lump sum can be left to heirs; most annuities cannot
• Investment confidence: if you are not confident investing, the annuity removes that risk
• Inflation: a fixed annuity loses purchasing power over time
• Taxes: both options are typically taxable as ordinary income when received