Annuity Deposit Calculator

An annuity deposit calculator answers the accumulation question: if you feed an annuity an initial deposit plus regular monthly contributions, how large is the balance when the saving phase ends? This one projects that growth month by month at a rate you set, nets out an annual fee, shows the full year-by-year ledger and a growth chart, then converts the final balance into an illustrative monthly income figure. It is the build-up tool, not a payout quote: the separate income calculator starts from a lump sum you already have.

Quick Answer

How to use the annuity deposit calculator

Set the starting deposit, the monthly amount and the term, pick a realistic net rate, then click Project Growth. The headline balance, the schedule and the chart all come from the same month-by-month run.

1. Initial deposit: the lump sum already in the contract, or the first check. Zero is allowed if you are building from contributions alone.
2. Monthly deposit: the recurring contribution. This tool models monthly deposits only; a quarterly or annual savings pattern needs its annual amount folded into the extra annual deposit field instead.
3. Extra annual deposit: a once-a-year top-up added at each year end, such as a bonus. The top-up is added the same way in both timing modes; the timing choice affects only the monthly deposits.
4. Growth rate and fee: the tool subtracts the annual fee from the growth rate and compounds the difference monthly. A 6% rate with a 1% fee is a 5% net projection, and if the fee is larger than the rate, the projected interest line goes negative.
5. Years: fractional years are rounded to the nearest whole year, and anything outside 1 to 50 is pulled back to that range. Blank, negative and non-numeric entries are treated as zero, so a blank years field runs a 1-year projection rather than an error.
6. Read all three tabs: the Calculator tab gives the balance, totals and verdict badge; the Growth Chart tab draws one bar per year; the Year Schedule tab lists each year’s deposits, interest and closing balance so you can audit the compounding yourself.

The accumulation formula this tool actually runs

The tool does not evaluate one closed-form formula. It simulates 12 monthly steps per year: each month the balance is multiplied by 1 + (rate − fee) ÷ 1200, and the monthly deposit is added either before that step (annuity due) or after it (ordinary annuity).

The closed-form check matters because it lets you verify the simulation by hand. At a 6% net rate, i is 0.005 and n is 240: the $10,000 start grows to about $33,102 and the $500 monthly stream grows to about $231,020, and the two sum to the tool’s $264,122.49. The income line at the bottom of the results is a separate, fixed calculation: whatever balance you project is spread over 240 monthly payments at 5%, regardless of the rate, term or fee you entered. It is a scale reference, not a payout quote, and lifetime income is a different question, handled by the annuity income calculator.

Worked example: $10,000 plus $500 a month for 20 years

The pre-filled example deposits $10,000 at the start, adds $500 at the end of every month, earns 6% with no fee, and runs for 20 years. The final balance is $264,122.49 on $130,000 of deposits, and the year-by-year ledger shows the compounding bending upward: year 1 adds $784.56 of interest, year 20 adds $15,153.57.

Three variations on the same deposits, each a real run of this calculator, show what each lever is worth. Switching to beginning-of-month deposits lifts the balance to $265,277.59. Adding a $2,000 top-up every year end lifts it to $339,034.50 on $170,000 deposited. And charging a 1% annual fee cuts it to $232,643.24, which is $31,479.25 less than the no-fee run for identical deposits. Time is the other big lever: at the same rate and deposits, most of the interest arrives in the second decade, which is what the compound interest doubling time calculator isolates.

Tax deferral: the annuity’s real edge, and its limit

Growth inside a deferred annuity is not taxed year by year. The Internal Revenue Service’s Publication 575, Pension and Annuity Income, sets out how annuity payments are taxed when the money comes out, and the SEC’s Investor.gov guide to annuities describes the accumulation and payout phases of the contract itself.

Deferral is a timing benefit, not a tax cut. Withdrawals from a non-qualified annuity are taxed as ordinary income on the earnings portion, and the IRS generally adds a 10% additional tax on amounts withdrawn before age 59½ unless an exception applies, as Publication 575 explains. Deposits themselves are not deductible outside a qualified plan. If the same saving sits inside an IRA instead, the tax treatment changes completely, which is why the Roth IRA investment calculator is the fair comparison for after-tax retirement saving.

Fees and surrender charges: what this projection leaves out

The fee field captures one thing only: a steady yearly percentage drag on the rate. It does not capture surrender charges, market value adjustments, or the caps, participation rates and spreads that decide what an indexed annuity actually credits in a given year.

That distinction matters when you price a real contract. Fixed annuities typically credit a declared rate and charge no explicit annual fee, so the rate you enter should already be the net figure. Variable annuities layer mortality and expense charges, fund costs and rider fees that commonly total well over 1% a year, and FINRA’s investor guide to annuities walks through those charges and the surrender periods that back them. Surrender charges are a separate exit cost for leaving early; they do not reduce a hold-to-term projection like this one, but they are the reason the projected balance is not money you can necessarily walk away with in the early years.

What this calculator covers, and why each part matters

This calculator projects the accumulation phase of an annuity, month by month, from the deposits you enter to the balance at the end of the saving phase, and then expresses that balance as the monthly figure it could support.

• Three deposit lines in one run. An initial deposit, monthly deposits, and an annual top-up are simulated together in one monthly run, with a full year schedule and chart, so a bonus or yearly extra does not need a separate calculation.
• The fee comes off the rate before compounding. The annual fee is subtracted from the growth rate and the difference compounds monthly. On the worked example, a 1% fee turns the 6% example into a 5% net projection and cuts the 20-year balance from $264,122.49 to $232,643.24, a difference of $31,479.25, which is why a projection that ignores fees overstates a variable annuity balance.
• Beginning/end timing. Deposits can be timed at the beginning of the month (annuity due) or the end of the month (ordinary annuity), and the timing choice is applied across the whole run.
• Ordinary-annuity and annuity-due formulas, shown as a schedule. The year schedule lists each year’s deposits, interest, and closing balance, and the chart draws one bar per year, so the compounding can be audited year by year.
• A fixed-basis income conversion. The final balance is also expressed as the monthly figure it could support, so the balance is not left as an abstract lump sum.

One boundary worth stating plainly: this page projects a balance. Valuing a stream of payments that grows each year is the reverse problem, covered by the present value of growing annuity calculator.

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