Compound interest & CAGR calculator
One growth model, solved four ways. Project what an initial amount plus monthly contributions becomes at an assumed annual return; recover the compound annual growth rate (CAGR) hiding between two values; ask how long until a target; or ask what monthly contribution a target requires. Every output is hypothetical arithmetic on the assumptions you type — the assumed return is yours, not ours, and none of this is a prediction or investment advice.
The 7% is an example assumption — edit it to your own. The balance compounds monthly at (1+r)^(1/12) − 1, so a lump sum grows exactly (1+r)^years.
Year-by-year table
| Year | Contributed | Value |
|---|---|---|
| 1 | $2,200.00 | $2,315.03 |
| 2 | $3,400.00 | $3,722.11 |
| 3 | $4,600.00 | $5,227.69 |
| 4 | $5,800.00 | $6,838.66 |
| 5 | $7,000.00 | $8,562.39 |
| 6 | $8,200.00 | $10,406.79 |
| 7 | $9,400.00 | $12,380.29 |
| 8 | $10,600.00 | $14,491.95 |
| 9 | $11,800.00 | $16,751.41 |
| 10 | $13,000.00 | $19,169.04 |
IMPORTANT: The projections generated by this calculator are hypothetical in nature, computed solely from the assumptions you entered. They do not reflect actual investment results and are not guarantees of future results. They exclude taxes, fees, and inflation. This is arithmetic on your inputs - not a Tickwind forecast or investment advice.
How the math works
- Monthly compounding at a disclosed rate: the balance grows by (1+r)^(1/12) − 1 each month, where r is your effective annual assumption — so a lump sum grows by exactly (1+r)^years ($10,000 at 7% for 10 years is $19,671.51).
- Contributions land at the start of each month and compound through the month they enter — the same convention as our DCA planner, so the two tools agree.
- CAGR = (end ÷ start)^(1 ÷ years) − 1 — the disclosed formula. It summarizes the two values you typed; it describes the past and forecasts nothing.
- Years-to-target runs the same month-by-month loop until the balance first meets the target, bounded at 100 years. A target the plan never reaches says so honestly — no fabricated number.
- Required-monthly is the closed-form annuity solve of the same model (at a 0% rate it reduces to simple division). All modes exclude taxes, fees and inflation.