Compound Interest Table: Year-by-Year Growth With Contributions

A compound interest table shows how a balance changes each year, separating your deposits from the interest earned. In the example below, a $1,000 starting balance plus $500 deposited at each year-end grows to $8,381.25 after ten years at a fixed 6% annual rate, compounded annually.

The table makes each step visible: opening balance, interest, contribution and closing balance. It also helps you check whether a growing total comes from your own deposits, earned interest or both.

Here is a fully specified example: $1,000 to start, a constant 6% nominal annual rate, interest compounded once a year, and another $500 deposited at the end of each year for ten years. There are no withdrawals, taxes, fees or rate changes. It is a teaching example, not a forecast or an available account offer.

• Total money deposited: $6,000, including the starting $1,000.
• Total interest: $2,381.25.
• Final balance: $8,381.25.

How to read the compound interest table

Begin with the opening balance. Multiply it by 6% to get that year's interest. Add the $500 end-of-year deposit after interest. The closing balance becomes the next year's opening balance. For year one, $1,000 earns $60. Add $500 at the end and the closing balance is $1,560. Year two starts at $1,560, earns $93.60, receives another $500, and closes at $2,153.60.

The order matters. Because the deposit is made at the end of each year, it does not earn interest during that year. If the same deposit were made at the beginning, each deposit would earn an additional year of interest. A useful table should always state the timing assumption rather than present one total as universally correct.

Year	Opening balance	Interest	End deposit	Closing balance
1	$1,000.00	$60.00	$500.00	$1,560.00
2	$1,560.00	$93.60	$500.00	$2,153.60
3	$2,153.60	$129.22	$500.00	$2,782.82
4	$2,782.82	$166.97	$500.00	$3,449.78
5	$3,449.78	$206.99	$500.00	$4,156.77
6	$4,156.77	$249.41	$500.00	$4,906.18
7	$4,906.18	$294.37	$500.00	$5,700.55
8	$5,700.55	$342.03	$500.00	$6,542.58
9	$6,542.58	$392.55	$500.00	$7,435.14
10	$7,435.14	$446.11	$500.00	$8,381.25

Displayed rows are rounded to cents; the underlying calculation carries full precision until the final result. That can make a displayed opening balance multiplied by 6% appear one cent different from a rounded interest cell in some years. Do not add rounded display cells and then treat any cent-level difference as a missing deposit.

What the totals say

Over ten years, you put in $6,000: the starting $1,000 plus ten deposits of $500. The closing balance is $8,381.25. The remaining $2,381.25 is interest produced under the stated fixed-rate model. The deposit column does not become “compound interest” merely because it appears in a compounding table.

Notice that annual interest grows from $60 in year one to $446.11 in year ten. Part of that growth comes from interest earning interest. Another part comes from the extra $500 added each year. A zero-rate comparison shows the effect of all interest, not just interest on interest. To isolate the extra growth from compounding, use a simple-interest comparison with the same deposits and timing. In this example, the starting $1,000 earns $600 over ten years at 6% simple interest. The year-end deposits earn $1,350 in total because they remain invested for nine years, eight years and so on down to zero. That produces $7,950, compared with $8,381.25 under compounding: a difference of $431.25. See the simple-versus-compound interest examples for the distinction.

The formula behind this table

With annual compounding and an equal deposit at the end of each year, the balance after n years is:

B = P(1 + r)^n + C[((1 + r)^n - 1) / r]

• P is the starting balance: $1,000.
• r is the annual rate as a decimal: 0.06.
• C is the deposit made at each year-end: $500.
• n is the number of years: 10.

The first term grows the starting balance. The second grows the series of deposits. Substituting the example's values gives $8,381.25 when rounded to cents. At a 0% rate, use B = P + Cn instead of dividing by zero.

This formula assumes the interest and deposit periods match. For monthly deposits, use the monthly-contributions walkthrough. For the effect of crediting interest more often, read the compounding-frequency comparison.

When does compound interest take off?

There is no mathematical switch that turns compounding on after a certain number of years. Interest on interest is present as soon as previously credited interest is included in the next calculation. The phrase “take off” usually describes a point where the yearly gain becomes noticeable to a particular reader or exceeds a chosen threshold. Different people will choose different thresholds.

In this example, year-one interest is only $60, while year-ten interest is about $446. But the fixed $500 deposit still exceeds the interest earned in year ten. If you define takeoff as yearly interest exceeding the yearly deposit, it has not happened in the ten-year table. If you define it as annual interest crossing $200, it occurs in year five. Neither definition is universal.

A higher rate, larger starting balance or longer period changes the timing. So does contribution timing. If the rate falls, returns are volatile or fees are charged, a smooth upward table can be misleading. Investment returns are not a fixed bank interest rate and may include losing years. Do not infer a guaranteed future “takeoff” from a constant-rate illustration.

Create and download your own compound interest table

ToolNimbly's compound interest calculator shows yearly opening balance, contributions, interest and closing balance. Enter the initial amount, annual nominal rate, duration and contribution amount, then select the compounding and contribution frequencies. Choose whether contributions arrive at the beginning or end of each period. To reproduce this table, enter 1,000 as the starting amount, 6 as the annual nominal rate and 10 as the duration in years. Select annual compounding, annual contributions of 500 and end-of-period timing.

If you model monthly deposits, do not compare its result directly with this annual-deposit table. Twelve $41.67 monthly deposits occur at different times from one $500 year-end deposit, and $41.67 times twelve is $500.04 rather than exactly $500. If you need to audit the figures, the calculator can export its yearly table as CSV. Check the assumptions shown on the page before sharing a projection.

One more useful check is to compare the closing balance with the sum of deposits plus cumulative interest. In year ten, $6,000 plus $2,381.25 equals $8,381.25. If those totals do not reconcile, look for an omitted starting balance, a deposit counted in the wrong year, or interest credited at a different frequency. A credible table should make that reconciliation possible without asking readers to trust a single headline figure.

What a table leaves out

A clean growth table usually assumes the same rate every year. Real savings rates can change. Investments can rise or fall. Taxes on interest or gains, account fees and inflation can reduce what the balance is worth or what it can buy. The example also assumes every deposit arrives on schedule. The Investor.gov compound interest calculator is another reference for exploring a starting balance, monthly contributions, rate and frequency, but its output is likewise driven by the assumptions entered.

Read any compound interest table in three passes: confirm the inputs and deposit timing, compare contributions with earned growth, then look for changes in the annual interest column. That gives you a clearer story than a final balance alone and helps you avoid mistaking your own deposits for returns.