Annuity Calculator: Should You Take the Lump Sum or Monthly Payments?

When a pension or annuity offers you a choice between a lump sum and monthly payments, you're being asked to bet on how long you'll live. Get this decision right and it's worth tens of thousands of dollars. Get it wrong and the cost is real.

The Core Tradeoff

Lump sum: You get a large amount now. You invest it, spend it as needed, and it may grow or decline. If you die early, there may be money left for heirs. If you live long, you risk running out.

Monthly payments (annuity): You get a guaranteed check every month for life. No investment risk, no running out. But if you die early, payments stop and heirs get nothing. If you live to 95, you collect far more than the lump sum would have provided.

Real Example: $500,000 Lump Sum vs $2,800/Month at Age 65

This is a realistic pension or annuity choice at retirement.

Option A: Take $500,000 lump sum Option B: Take $2,800/month ($33,600/year) for life

Break-Even Analysis

To find the break-even point, you need to know when the cumulative monthly payments equal the lump sum value.

Simple break-even (ignoring investment return on lump sum): $500,000 / $2,800 = 178.6 months = 14.9 years

At age 65, break-even is age 79.9.

If you live past ~80, the monthly payments win in total dollars collected. If you die before 80, the lump sum would have been worth more to your estate.

US life expectancy at 65 is approximately 84 for men, 87 for women. Most 65-year-olds will exceed the break-even point.

Investment Return Matters

The lump sum calculation changes if you invest the $500,000. If invested at 5% annually:

| Age | Lump Sum Invested at 5% | Cumulative Annuity Payments | |-----|------------------------|-----------------------------| | 70 | $638,000 | $168,000 | | 75 | $814,000 | $336,000 | | 80 | $1,039,000 | $504,000 | | 85 | $1,326,000 | $672,000 | | 90 | $1,691,000 | $840,000 |

Wait. If the lump sum grows to $1.3M at 85, that's far more than the $672,000 in annuity payments received. The lump sum wins, right?

Not exactly. The comparison isn't just total value. It's total income generated. To spend from the lump sum, you have to draw it down. The annuity is $2,800/month forever without touching principal.

Using a 4% withdrawal from the invested lump sum:

• $500,000 x 4% = $20,000/year = $1,667/month

The annuity pays $2,800/month. On a pure income comparison, the annuity wins by $1,133/month as long as you live.

Inflation Erosion: The Annuity's Biggest Weakness

Most fixed annuities do not adjust for inflation. The $2,800/month you receive at 65 will have the purchasing power of roughly:

• $2,376 at age 73 (3% inflation, 8 years)
• $2,010 at age 81 (3% inflation, 16 years)
• $1,700 at age 89 (3% inflation, 24 years)

Over a 25-year retirement, 3% inflation cuts your annuity's real value nearly in half. The lump sum invested in equities has a better chance of keeping pace with inflation.

This is the core argument for the lump sum: long-term inflation protection and potential for real growth.

Factors Favoring the Annuity

• Health concerns: If your health is poor and you expect a shorter retirement, guaranteed monthly income beats an investment account that may outlast you.
• No investment discipline: If you're prone to overspending or risky investing, a forced monthly payment prevents both.
• Simplicity: No investment decisions. No sequencing risk. The check arrives regardless of markets.
• Spouse or survivor benefit: Many pensions offer a reduced payment that continues to a surviving spouse. Factor this into the comparison.

Factors Favoring the Lump Sum

• Good health and family longevity: If your family lives to 95+, compounding investment returns over 30 years can dwarf fixed annuity income.
• Inflation concerns: A fixed annuity erodes in real value. An invested portfolio can grow above inflation.
• Legacy goals: Unused lump sum balance passes to heirs. Most annuities don't.
• Financial sophistication: If you can invest consistently in low-cost index funds without emotional decision-making, the math often favors the lump sum.

The Hybrid Approach

You don't have to choose entirely one or the other. A common strategy:

1. Delay Social Security to 70 to maximize your guaranteed inflation-adjusted income floor
2. Take the pension lump sum and invest it
3. Use the Social Security benefit for living expenses, letting the portfolio grow

This gives you both inflation-protected guaranteed income (Social Security) and the growth potential of the lump sum.

Run the Numbers

Use the Compound Interest Calculator to model what your lump sum grows to over time at various rates. Compare the projected portfolio value against cumulative annuity payments to find your personal break-even.