年金計算機

An annuity is a financial contract between you and an insurance company. During the accumulation phase, you invest money that grows tax-deferred. During the payout (annuitization) phase, the insurer pays you a regular income stream. Annuities are commonly used for retirement planning to guarantee income you cannot outlive.

A fixed annuity offers a guaranteed interest rate and predictable growth, making it lower risk. A variable annuity invests in sub-accounts similar to mutual funds, so returns fluctuate with the market. Variable annuities have higher growth potential but also more risk. This calculator models both so you can compare projected outcomes.

In a tax-deferred annuity, you don't pay taxes on investment gains each year. This lets your entire balance compound without tax drag. Over decades, this advantage can be substantial. For example, at a 6% return and 25% tax rate over 20 years, tax deferral can result in tens of thousands of dollars more in your account compared to a taxable investment.

Payout amounts are calculated using the present value of an annuity formula: PMT = PV x r / (1 - (1 + r)^-n), where PV is your account balance, r is the interest rate per period, and n is the total number of payment periods. This ensures your balance is fully distributed over the chosen payout period while continuing to earn interest.

Annuities are worth considering if you've maxed out other tax-advantaged accounts (401k, IRA), want guaranteed retirement income, or are concerned about outliving your savings. They work best as part of a diversified retirement strategy. Deferred annuities are most effective when purchased 10-30 years before retirement to maximize tax-deferred compounding.

Common annuity fees include mortality and expense charges (1-1.5%), administrative fees, fund management fees for variable annuities (0.5-2%), and surrender charges for early withdrawal (typically 5-10% declining over 5-10 years). This calculator shows gross returns before fees. Subtract roughly 1-2.5% from the interest rate to estimate after-fee performance for variable annuities.