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3 scenarios side by side, inflation-adjusted, milestone chart.
| Year | Contributed | Interest this year | Balance | Real value |
|---|---|---|---|---|
| 1 | $16,000.00 | $518.65 | $16,518.65 | $16,037.52 |
| 2 | $22,000.00 | $784.23 | $23,302.87 | $21,965.19 |
| 3 | $28,000.00 | $1,060.63 | $30,363.50 | $27,786.90 |
| 4 | $34,000.00 | $1,348.29 | $37,711.79 | $33,506.43 |
| 5 | $40,000.00 | $1,647.67 | $45,359.46 | $39,127.46 |
| 6 | $46,000.00 | $1,959.25 | $53,318.70 | $44,653.57 |
| 7 | $52,000.00 | $2,283.52 | $61,602.22 | $50,088.24 |
| 8 | $58,000.00 | $2,621.00 | $70,223.22 | $55,434.86 |
| 9 | $64,000.00 | $2,972.23 | $79,195.45 | $60,696.72 |
| 10 | $70,000.00 | $3,337.78 | $88,533.23 | $65,877.04 |
| 11 | $76,000.00 | $3,718.21 | $98,251.44 | $70,978.93 |
| 12 | $82,000.00 | $4,114.15 | $108,365.59 | $76,005.44 |
| 13 | $88,000.00 | $4,526.21 | $118,891.80 | $80,959.53 |
| 14 | $94,000.00 | $4,955.07 | $129,846.87 | $85,844.08 |
| 15 | $100,000.00 | $5,401.39 | $141,248.26 | $90,661.88 |
| 16 | $106,000.00 | $5,865.90 | $153,114.16 | $95,415.68 |
| 17 | $112,000.00 | $6,349.34 | $165,463.50 | $100,108.14 |
| 18 | $118,000.00 | $6,852.47 | $178,315.97 | $104,741.84 |
| 19 | $124,000.00 | $7,376.10 | $191,692.07 | $109,319.31 |
| 20 | $130,000.00 | $7,921.06 | $205,613.13 | $113,843.01 |
| 21 | $136,000.00 | $8,488.23 | $220,101.36 | $118,315.33 |
| 22 | $142,000.00 | $9,078.50 | $235,179.86 | $122,738.61 |
| 23 | $148,000.00 | $9,692.82 | $250,872.68 | $127,115.12 |
| 24 | $154,000.00 | $10,332.17 | $267,204.86 | $131,447.08 |
| 25 | $160,000.00 | $10,997.57 | $284,202.43 | $135,736.66 |
| 26 | $166,000.00 | $11,690.08 | $301,892.50 | $139,985.96 |
| 27 | $172,000.00 | $12,410.80 | $320,303.30 | $144,197.04 |
| 28 | $178,000.00 | $13,160.88 | $339,464.18 | $148,371.90 |
| 29 | $184,000.00 | $13,941.53 | $359,405.71 | $152,512.50 |
| 30 | $190,000.00 | $14,753.97 | $380,159.68 | $156,620.76 |
A compound interest calculator shows how money grows when interest earns interest. Plug in a principal, an annual rate, a contribution schedule, and a time horizon. The calculator returns the nominal balance year by year, the inflation-adjusted real value, and a chart that overlays the contribution-vs-growth split so you can see exactly when interest takes over from saving.
This calculator runs three scenarios at once (default conservative 4%, balanced 7%, aggressive 10%) so you can compare investment strategies side by side. It accounts for inflation, contribution growth from raises, and four compounding frequencies. Everything runs in your browser, no signup, no quota.
Most calculators run one. NerdWallet, Investor.gov, BankRate all show a single line. We show three so you can pick by comparing, not by guessing.
Most free calculators show the nominal number only. A $1M projection at 30 years feels great until you realize 3% inflation cuts it to $412K of buying power. We show both.
No affiliate links to brokerages or robo-advisors. We don't earn anything by pushing you to a higher-risk option. The math is the math.
Investor.gov lets you save scenarios but ties them to an account. We let you tune and re-tune freely with no friction.
| Feature | Molixa | NerdWallet | Investor.gov | BankRate |
|---|---|---|---|---|
| Multiple scenarios side by side | 3 at once | 1 | 1 | 1 |
| Inflation-adjusted real return | Yes, toggle | No | Partial | No |
| Contribution growth modeling | Yes | No | No | No |
| 4 compounding frequencies | Yes | Yes | Yes | Yes |
| Milestone markers on chart | 5/10/20/30/40/50 | Annual only | Annual only | Annual only |
| Contribution vs growth shading | Yes | No | No | No |
| Affiliate links / push to product | None | Many | None | Many |
| No signup | Yes | Yes | Yes | Yes |
Yes. Unlimited use, no signup, no daily cap. All math runs in your browser. NerdWallet's calculator is free but limited to one scenario at a time and pushes you toward affiliate products; ours runs three scenarios side by side and recommends nothing.
Interest you earn on both the original deposit and the interest already added to it. After year 1, you earn interest on a slightly bigger pile. After year 2, an even bigger pile. Over decades the curve gets steep. That is the engine behind every retirement account.
The formula is A = P(1 + r/n)^(nt) where P is principal, r is annual rate, n is compounding periods per year, t is years. We compound daily, monthly, quarterly, or yearly per your choice, layer in periodic contributions, and round to whole cents at year ends.
Yes. The tool runs three scenarios in parallel: a conservative 4%, a balanced 7%, and an aggressive 10% are the defaults. You can rename, retune, or zero-out any of them. The chart overlays all three for visual comparison.
Your nominal balance is the dollar number on the screen. Real balance subtracts inflation, showing how much that money will actually buy in today's purchasing power. A $1M nest egg in 30 years at 3% inflation is only worth ~$412K in today's dollars.
Default 3% is the long-term US average. Plug in 2% for a more optimistic view, 4-5% for a conservative one. Recent years (2021-2023) saw 5-9% inflation, but that is unusual; 3% is a reasonable long-horizon default.
Weekly, biweekly (matches most paychecks), monthly, annual, or none. The math compounds contributions per their period, so a $500 monthly contribution grows slightly differently than a $6000 annual contribution at the same rate.
Yes. Set 'contribution growth' to 2% to grow your contribution by 2% each year (matching a typical raise). Most retirement calculators only model flat contributions, which understates what you'll actually save.
APR is the simple annual rate. APY (annual percentage yield) accounts for compounding within the year. A 5% APR compounded monthly equals about 5.12% APY. We label our input as the annual rate and apply your chosen compounding frequency on top.
No. The form, the math, the chart, all run in your browser. Your principal, your rates, your savings goals stay on your laptop. We don't even know you ran the calculator.
Three scenarios, inflation-adjusted, milestone markers, free unlimited. No signup, no affiliate steering.
Open the compound interest calculatorThe Compound Interest Calculator page is built, reviewed, and maintained by the Molixa team. We use the tool we ship and update the docs when the behavior changes.