Annuity Calculator

Determine annuity payout amounts, fixed term payments, or lifetime distributions.

Status: Algorithmic Audit (CPA Review Pending)
Jurisdiction: United States (IRS & SSA Standards)
Tax Year / Constants: 2026 Statutory Limits
Data Privacy: 100% Client-Side In-Browser

The Mathematical Formula

Monthly Annuity Payout = Principal Purchase Price × [ r / (1 - (1 + r)⁻ⁿ) ]

Variable & Parameter Definitions

  • Monthly Annuity Payout The guaranteed fixed monthly distribution paid to the annuitant for life or a fixed period.
  • Principal Purchase Price Single lump-sum premium paid to the insurance carrier to purchase the annuity contract.
  • r Periodic interest rate credit internal to the insurance company annuity pricing contract.
  • n Actuarial life expectancy or guaranteed term expressed in monthly payment intervals.

Real-World Worked Scenario: $250,000 Single Premium Immediate Annuity (SPIA) at Age 65

A 65-year-old retiree purchases a $250,000 immediate lifetime annuity with a 6.8% annual payout rate.

  1. Annual Guaranteed Payout: $250,000 × 0.068 = $17,000 per year.
  2. Monthly Guaranteed Income: $17,000 ÷ 12 = $1,416.67 per month for life.
  3. Exclusion Ratio (Taxable vs Non-Taxable): A portion of each payment represents tax-free return of principal, while the remainder is taxed as ordinary income.
  4. Mortality Credit Benefit: If the annuitant lives to age 90 (25 years), total payments collected equal $425,000 on a $250,000 original premium.
Key Financial Takeaway: Annuities transfer longevity risk to an insurance company, guaranteeing cash flow regardless of market crashes or living past age 95.

Strategic Insights & Pitfalls to Avoid

  • ✓ Inflation Vulnerability: Fixed annuities without COLA riders lose purchasing power over 20+ year horizons due to inflation.
  • ✓ State Guaranty Association Coverage: Insurance carriers are backed by state guaranty associations (typically up to $250,000 to $300,000 per carrier); split larger sums across carriers.
  • ✓ Surrender Charges: Deferred annuities carry heavy surrender penalty charges (up to 7% to 10%) if funds are withdrawn during early contract years.

Frequently Asked Questions

What is the difference between an immediate annuity and a deferred annuity?

An immediate annuity starts paying income within 1 to 12 months of purchase. A deferred annuity accumulates interest over years before annuitizing into income later.

What happens to my annuity when I die?

Under a straight life annuity, payments cease upon death. Under a "period certain" or "cash refund" rider, remaining funds pass to named beneficiaries.

How are annuity payouts taxed?

For annuities purchased with non-qualified after-tax dollars, payments are split between tax-free return of principal and taxable interest earnings.

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