Annuity Income Calculator - Estimate Your Monthly Payout From Any Principal
An annuity converts a lump sum into a guaranteed stream of periodic income. The formula: Periodic Income = Principal x [r(1+r)^n / ((1+r)^n - 1)]. Where r = periodic interest rate and n = total number of payment periods.
The Formula Explained
Worked example: Thomas invests $250,000 in a 20-year annuity at 5 percent. Monthly rate r = 0.004167. Total periods n = 240. Monthly Payment = $250,000 x 0.006600 = $1,650/month. Total payments: $396,000 on $250,000 principal.
| Principal | Term | Rate | Monthly Payment |
|---|---|---|---|
| $100,000 | 10 years | 4% | $1,012 |
| $100,000 | 20 years | 4% | $606 |
| $250,000 | 20 years | 5% | $1,650 |
| $500,000 | 25 years | 5% | $2,923 |
How to Use This Calculator on CalcAdvisor.com
Access the calculator at https://www.calcadvisor.com/calculators/annuity-income-calculator.
3 Real-World Examples
Example 1: Helen, 67, Converting Part of Her IRA to Guaranteed Income
Helen uses $300,000 of her $850,000 IRA to purchase an immediate annuity at 5.2 percent for 20 years. Monthly payment: $2,008. Combined with Social Security ($1,900) and remaining IRA withdrawals ($1,833): total $5,741/month against $4,800 expenses.
Example 2: Robert and Carol, Evaluating a Pension Lump Sum
Robert's employer offers $420,000 lump sum OR $2,350/month for life. The implied rate on the lump sum (6.1 percent) exceeds market annuity rates (5.2 percent), meaning the pension monthly option is financially superior.
Example 3: Margaret, 72, Managing RMDs With a QLAC
Margaret invests $200,000 in a QLAC, removing it from RMD calculations. At age 85 the QLAC begins paying $2,800/month - precisely when healthcare costs are most likely to spike.
Common Mistakes to Avoid
- Confusing the annuity payout rate with an investment return.
- Annuitizing all of your savings with no liquid reserve.
- Not shopping multiple insurers for annuity quotes.
- Ignoring inflation risk in fixed annuities.
- Not considering insurer financial strength ratings.
- Purchasing a variable or indexed annuity without fully understanding the fee structure.
- Failing to consider the tax treatment of annuity payments.
Final Thoughts
Visit https://www.calcadvisor.com/calculators/annuity-income-calculator to calculate periodic income from any principal using the correct annuity factor formula.