Annuity Calculator

Estimate annuity accumulation before withdrawals begin.

Accumulate a starting balance with monthly and annual contributions.

Result

Annuity future value$338,976.17

Starting principal$100,000.00

Total additions$44,000.00

Total contributions$144,000.00

Growth$194,976.17

The first row’s addition includes starting principal. Annual additions occur at the beginning or end of each saving year; monthly additions use the same selected timing. The final partial year receives an annual deposit only if its scheduled deposit date is reached.

Calculation details

Scroll horizontally or vertically to see more. Download CSV for the complete schedule.

Month	Addition including initial principal	Investment return	Ending balance
1	100,100	407.41	100,507.41
2	100	409.48	101,016.89
3	100	411.56	101,528.45
4	100	413.64	102,042.09
5	100	415.73	102,557.82
6	100	417.83	103,075.65
7	100	419.94	103,595.60
8	100	422.06	104,117.66
9	100	424.19	104,641.84
10	100	426.32	105,168.17
11	100	428.47	105,696.64
12	1,100	430.62	107,227.26
13	100	436.86	107,764.11
14	100	439.04	108,303.16
15	100	441.24	108,844.40
16	100	443.45	109,387.85
17	100	445.66	109,933.50
18	100	447.88	110,481.39
19	100	450.11	111,031.50
20	100	452.36	111,583.86
21	100	454.61	112,138.46
22	100	456.87	112,695.33
23	100	459.13	113,254.47
24	1,100	461.41	114,815.88
25	100	467.77	115,383.65
26	100	470.09	115,953.74
27	100	472.41	116,526.15
28	100	474.74	117,100.89
29	100	477.08	117,677.98
30	100	479.43	118,257.41
31	100	481.80	118,839.21
32	100	484.17	119,423.37
33	100	486.55	120,009.92
34	100	488.94	120,598.85
35	100	491.33	121,190.19
36	1,100	493.74	122,783.93

How to use this calculator

Accumulate a starting balance with monthly and annual contributions. Enter amounts in the units shown, select the applicable options, and click Calculate. Use Reset to restore the starting values.

Calculation formula

Monthly and annual annuity accumulation factors use their respective periodic rates.

Assumptions and accuracy

Review timing, rates, fees and result notes when comparing scenarios. Future returns and rates are assumptions rather than guaranteed outcomes. Monetary display follows the currency’s precision; intermediate calculations retain additional digits.

Choose what to calculate

Annuity calculator with monthly contributions

Project annuity accumulation with starting principal and scheduled monthly or annual contributions. This model does not include insurer charges or income-tax rules.

Open this calculation

Understanding this calculation

Estimate an annuity accumulation balance from starting money and recurring annual or monthly contributions. Distinguish contributions from growth before comparing scenarios.

Worked examples

Accumulate an annuity with monthly contributions

Illustrative inputs are specified in the steps below; the example link loads the complete settings. Unmentioned settings use the linked defaults.

Opening 1,000 plus twelve deposits of 100 gives 2,200 when the assumed return is zero. This is an accumulation illustration, not an insurance quote.

Annuity future value: 2,200 USD.

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Common questions

Can I enter both annual and monthly annuity contributions?

Yes, but they are separate cash streams. Entering the same saving in both fields would double-count it.

Does the assumed annuity return represent a guarantee?

No. A typed return is a modeling assumption; an actual guarantee depends on the specific contract and issuer.

Scope and assumptions

This is an accumulation model, not a quote for a guaranteed insurance product. Contract fees, surrender provisions and taxes are not fully represented.

Sources

Calculation notes checked October 20, 2026. Examples are mathematical checks under the stated assumptions.

Calculation methods and formulas

Annuity Accumulation