Annuity Calculator

Modify the values and click the Calculate button to use

End Balance: $175,533.38

End Balance: $175,533.38
Starting Principal: $20,000.00
Total Additions: $100,000.00
Total Interest: $55,533.38

68% Principal32% Interest

Annuity schedule

Year	Date	Additions	Interest	Ending balance
1	Nov 2027	$10,000.00	$1,800.00	$31,800.00
2	Nov 2028	$10,000.00	$2,508.00	$44,308.00
3	Nov 2029	$10,000.00	$3,258.48	$57,566.48
4	Nov 2030	$10,000.00	$4,053.99	$71,620.47
5	Nov 2031	$10,000.00	$4,897.23	$86,517.70
6	Nov 2032	$10,000.00	$5,791.06	$102,308.76
7	Nov 2033	$10,000.00	$6,738.53	$119,047.28
8	Nov 2034	$10,000.00	$7,742.84	$136,790.12
9	Nov 2035	$10,000.00	$8,807.41	$155,597.53
10	Nov 2036	$10,000.00	$9,935.85	$175,533.38

Balance, additions, and interest over time

Balance
Interest
Additions

What this annuity calculator does

This calculator projects the value of an annuity over time. It combines a starting principal, annual additions, monthly additions, a growth rate, and a payment timing choice. Additions can be made at the beginning or end of each period.

The result shows the ending balance, total additions, and interest earned. It is a planning estimate, not a quote for a specific annuity contract.

How to use this calculator

Enter the starting principal.
Enter any annual or monthly addition.
Choose whether additions are made at the beginning or end of each period.
Enter the annual growth rate and the number of years.
Click Calculate.

The default example starts with $20,000, adds $10,000 at the beginning of each year for 10 years, and earns 6% per year. The ending balance is $175,533.38.

Annuity growth formula

For annual additions at the beginning of each year:

End balance = P × (1 + g)^n + A × (1 + g) × ((1 + g)^n − 1) / g

P is the starting principal, A is the annual addition, g is the annual growth rate, and n is the number of years. For end-of-year additions, remove the extra (1 + g) factor.

Monthly additions are applied each month. The annual growth rate is converted to an effective monthly rate so the timing of each addition is consistent.

What the results include

End balance: the projected annuity value.
Starting principal: the initial amount.
Total additions: the annual and monthly contributions, excluding the starting principal.
Total interest: the ending balance minus principal and additions.
Annuity schedule: yearly additions, interest, and ending balance.
Growth chart: balance, cumulative additions, and cumulative interest.

Assumptions and limitations

The calculator assumes a constant growth rate and additions that occur on a regular annual or monthly schedule. It does not include taxes, fees, surrender charges, mortality credits, inflation, or variable annuity features. The result is a nominal balance, not a guaranteed contract value.

Frequently asked questions

What is the difference between beginning and end-of-period additions?

Beginning-of-period additions have one extra period to grow. The ending balance is slightly higher than with end-of-period additions.

Does this calculator price a real annuity?

No. It projects the accumulation of a principal and additions. A real annuity quote depends on the insurer, contract terms, payout options, and mortality assumptions.

Are annuity earnings tax-deferred?

Many annuities have tax-deferred growth, but the tax treatment depends on the contract and the account. This calculator does not model taxes.

What happens if the growth rate is 0%?

The ending balance equals the starting principal plus all additions. No interest is earned.

Source

References:

Disclaimer

This calculator is for informational and planning purposes only. It is not financial or investment advice. Annuity contracts involve fees and terms that are not modeled here.

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