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This calculator is part of the finance section. Keep the current tool open for calculation, then use the related calculators below to compare nearby planning tasks.

Finance calculator

Compound Interest Calculator

Use a fuller compound interest calculator when you want to see how principal, recurring additions, and compounding work together over time.

compoundinterestgrowth

Calculate

Choose growth and contribution assumptions

The reference page uses a traditional calculate-and-jump layout. Here the same compounding logic stays live on one screen so you can change the rate, term, or contribution timing without losing the charts and tables.

Quick summary

Compound interest summary

This summary keeps the same outcome focus as the classic page, but surfaces the contributions, effective growth, and real buying power without a separate result jump.

Ending balance$71,469.94

Total principal$39,000.00

Total recurring contributions$27,000.00

Total interest$32,469.94

Effective annual yield5.96%

Buying power after inflation$49,347.53

Balance composition

Principal, additions, and earned interest

This percentage ring shows how much of the final balance comes from the starting principal, added contributions, and compound interest.

Ending balance$71,469.94

17%

Initial principal

$12,000.00

38%

Recurring additions

$27,000.00

45%

Compound interest

$32,469.94

Growth path

Balance buildup over time

Each bar tracks how the balance changes year by year as new additions and compounding stack on top of the initial principal.

114.6K

217.3K

320.2K

423.2K

526.4K

629.9K

733.5K

837.3K

941.4K

1045.7K

1150.3K

1255.1K

1360.3K

1465.7K

1571.5K

Initial principal

Recurring additions

Compound interest

Monthly preview

Monthly compound-interest schedule

The first 120 months are shown here so you can see how each deposit and interest credit changes the balance.

Month	Deposit	Interest	Ending balance
1	$150.00	$58.00	$12,208.00
2	$150.00	$59.01	$12,417.01
3	$150.00	$60.02	$12,627.02
4	$150.00	$61.03	$12,838.05
5	$150.00	$62.05	$13,050.10
6	$150.00	$63.08	$13,263.18
7	$150.00	$64.11	$13,477.28
8	$150.00	$65.14	$13,692.42
9	$150.00	$66.18	$13,908.60
10	$150.00	$67.22	$14,125.83
11	$150.00	$68.27	$14,344.10
12	$150.00	$69.33	$14,563.43
13	$150.00	$70.39	$14,783.82
14	$150.00	$71.46	$15,005.28
15	$150.00	$72.53	$15,227.80
16	$150.00	$73.60	$15,451.40
17	$150.00	$74.68	$15,676.09
18	$150.00	$75.77	$15,901.85
19	$150.00	$76.86	$16,128.71
20	$150.00	$77.96	$16,356.67
21	$150.00	$79.06	$16,585.73
22	$150.00	$80.16	$16,815.89
23	$150.00	$81.28	$17,047.17
24	$150.00	$82.39	$17,279.56
25	$150.00	$83.52	$17,513.08
26	$150.00	$84.65	$17,747.73
27	$150.00	$85.78	$17,983.51
28	$150.00	$86.92	$18,220.43
29	$150.00	$88.07	$18,458.49
30	$150.00	$89.22	$18,697.71
31	$150.00	$90.37	$18,938.08
32	$150.00	$91.53	$19,179.61
33	$150.00	$92.70	$19,422.32
34	$150.00	$93.87	$19,666.19
35	$150.00	$95.05	$19,911.24
36	$150.00	$96.24	$20,157.48
37	$150.00	$97.43	$20,404.91
38	$150.00	$98.62	$20,653.53
39	$150.00	$99.83	$20,903.36
40	$150.00	$101.03	$21,154.39
41	$150.00	$102.25	$21,406.64
42	$150.00	$103.47	$21,660.10
43	$150.00	$104.69	$21,914.79
44	$150.00	$105.92	$22,170.71
45	$150.00	$107.16	$22,427.87
46	$150.00	$108.40	$22,686.27
47	$150.00	$109.65	$22,945.93
48	$150.00	$110.91	$23,206.83
49	$150.00	$112.17	$23,469.00
50	$150.00	$113.43	$23,732.43
51	$150.00	$114.71	$23,997.14
52	$150.00	$115.99	$24,263.12
53	$150.00	$117.27	$24,530.39
54	$150.00	$118.56	$24,798.96
55	$150.00	$119.86	$25,068.82
56	$150.00	$121.17	$25,339.99
57	$150.00	$122.48	$25,612.46
58	$150.00	$123.79	$25,886.26
59	$150.00	$125.12	$26,161.37
60	$150.00	$126.45	$26,437.82
61	$150.00	$127.78	$26,715.60
62	$150.00	$129.13	$26,994.73
63	$150.00	$130.47	$27,275.20
64	$150.00	$131.83	$27,557.03
65	$150.00	$133.19	$27,840.22
66	$150.00	$134.56	$28,124.79
67	$150.00	$135.94	$28,410.72
68	$150.00	$137.32	$28,698.04
69	$150.00	$138.71	$28,986.75
70	$150.00	$140.10	$29,276.85
71	$150.00	$141.50	$29,568.36
72	$150.00	$142.91	$29,861.27
73	$150.00	$144.33	$30,155.60
74	$150.00	$145.75	$30,451.35
75	$150.00	$147.18	$30,748.53
76	$150.00	$148.62	$31,047.15
77	$150.00	$150.06	$31,347.21
78	$150.00	$151.51	$31,648.72
79	$150.00	$152.97	$31,951.69
80	$150.00	$154.43	$32,256.12
81	$150.00	$155.90	$32,562.03
82	$150.00	$157.38	$32,869.41
83	$150.00	$158.87	$33,178.28
84	$150.00	$160.36	$33,488.64
85	$150.00	$161.86	$33,800.51
86	$150.00	$163.37	$34,113.87
87	$150.00	$164.88	$34,428.76
88	$150.00	$166.41	$34,745.16
89	$150.00	$167.93	$35,063.10
90	$150.00	$169.47	$35,382.57
91	$150.00	$171.02	$35,703.59
92	$150.00	$172.57	$36,026.15
93	$150.00	$174.13	$36,350.28
94	$150.00	$175.69	$36,675.97
95	$150.00	$177.27	$37,003.24
96	$150.00	$178.85	$37,332.09
97	$150.00	$180.44	$37,662.53
98	$150.00	$182.04	$37,994.56
99	$150.00	$183.64	$38,328.20
100	$150.00	$185.25	$38,663.46
101	$150.00	$186.87	$39,000.33
102	$150.00	$188.50	$39,338.83
103	$150.00	$190.14	$39,678.97
104	$150.00	$191.78	$40,020.75
105	$150.00	$193.43	$40,364.18
106	$150.00	$195.09	$40,709.28
107	$150.00	$196.76	$41,056.04
108	$150.00	$198.44	$41,404.48
109	$150.00	$200.12	$41,754.60
110	$150.00	$201.81	$42,106.41
111	$150.00	$203.51	$42,459.93
112	$150.00	$205.22	$42,815.15
113	$150.00	$206.94	$43,172.09
114	$150.00	$208.67	$43,530.75
115	$150.00	$210.40	$43,891.15
116	$150.00	$212.14	$44,253.29
117	$150.00	$213.89	$44,617.18
118	$150.00	$215.65	$44,982.83
119	$150.00	$217.42	$45,350.25
120	$150.00	$219.19	$45,719.44

Compounding is set to Monthly (APR), and deposits are scheduled at the end of each compounding period.

Yearly summary

Year-end accumulation summary

Year	Deposit	Interest	Ending balance
1	$13,800.00	$763.43	$14,563.43
2	$1,800.00	$916.13	$17,279.56
3	$1,800.00	$1,077.92	$20,157.48
4	$1,800.00	$1,249.35	$23,206.83
5	$1,800.00	$1,430.99	$26,437.82
6	$1,800.00	$1,623.45	$29,861.27
7	$1,800.00	$1,827.37	$33,488.64
8	$1,800.00	$2,043.45	$37,332.09
9	$1,800.00	$2,272.39	$41,404.48
10	$1,800.00	$2,514.97	$45,719.44
11	$1,800.00	$2,772.00	$50,291.44
12	$1,800.00	$3,044.34	$55,135.78
13	$1,800.00	$3,332.90	$60,268.68
14	$1,800.00	$3,638.65	$65,707.33
15	$1,800.00	$3,962.61	$71,469.94

How to use this calculator

Compound interest guide

Compound interest means interest is earned on both the original principal and on previously earned interest. That is why balances can accelerate over time, especially when contributions keep being added along the way. This page follows the same compounding idea as the reference calculator, but keeps the result, schedule, and visual breakdown on one live screen instead of making you jump to a separate result block.

Start with the initial principal, then add annual or monthly contributions to model how new money enters the balance over time.
Choose the compounding frequency carefully, because the same nominal rate can produce different results depending on whether interest compounds annually, monthly, daily, or continuously.
Use tax and inflation fields when you want the projection to reflect after-tax growth and the future buying power of the ending balance, not just the nominal account total.

Formula / method

Compound interest adds earned interest back into the balance, so later periods can earn on both principal and prior growth. Contribution timing and compounding frequency both matter.

Growth is calculated period by period with compounding.
Recurring contributions are added according to the selected schedule.
The chart separates what came from principal and what came from growth.

Example calculation

Review the current live example

The example below reflects the current values shown in the calculator above, so it updates as you change the form without altering the calculation logic itself.

Example inputs

Initial principal12,000

Annual addition0

Monthly addition150

Deposit timingEnd of each compounding period

Estimated annual rate of return (%)5.8

Example outputs

Ending balance$71,469.94

Total principal$39,000.00

Total recurring contributions$27,000.00

Total interest$32,469.94

Disclaimer

Use results as planning guidance only

Results are for reference only and do not constitute financial, investment, tax, or legal advice. Product terms, lender rules, tax treatment, and fees can vary in real situations.

Do not treat calculator output as financial, investment, medical, or legal advice.
Check assumptions, dates, tax rules, and provider-specific terms before acting on a result.
Use official documents or professional guidance when the decision has material consequences.

FAQ

Common Compound Interest questions

Why is compound interest different from simple interest?

Simple interest applies the rate only to the original principal, while compound interest applies interest to both the principal and previously earned interest.

Why does compounding frequency matter?

More frequent compounding generally produces a higher ending balance because interest is credited to the account more often.

Why does this page update live instead of jumping to the result section?

The reference page uses a calculate-first workflow. Here the same compounding logic stays on one screen so you can compare assumptions without losing the table or chart context.

Compound Interest Calculator

Choose growth and contribution assumptions

Compound interest summary

Principal, additions, and earned interest

Balance buildup over time

Monthly compound-interest schedule

Year-end accumulation summary

Compound interest guide

Formula / method

Review the current live example

Example inputs

Example outputs

Use results as planning guidance only

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Common Compound Interest questions

Why is compound interest different from simple interest?

Why does compounding frequency matter?

Why does this page update live instead of jumping to the result section?

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