| Year | Contributions | Interest earned | Ending balance |
|---|
PV × (1+r)^n; a regular payment adds PMT × ((1+i)^N − 1) / i (times 1+i if you contribute at the start of each period). ROI is gain ÷ original cost. IRR is the rate that sets NPV of your cash-flow list to zero; payback is when the cumulative sum crosses zero. You type the rate and cash flows — not investment advice.
Future value of a lump sum uses the standard compound interest formula: PV × (1+r)^n. If you're also contributing a regular payment on top, that adds PMT × ((1+i)^N − 1) / i, adjusted by a factor of (1+i) if your contributions happen at the start of each period rather than the end.
ROI (return on investment) is simply your gain divided by your original cost, expressed as a percentage — a straightforward way to compare how much you got back relative to what you put in, regardless of how long the investment took.
IRR (internal rate of return) is the discount rate that makes the net present value of your entire cash-flow list equal to zero — found through iterative calculation rather than a direct formula. Payback period is simply when your cumulative cash flow first crosses from negative to positive. You supply the rate and cash flows yourself throughout; this models the maths of compounding and returns, not investment advice on what to actually invest in.
ROI is a simple ratio of total gain to original cost, without regard to timing. IRR accounts for the timing of cash flows over multiple periods, finding the effective annual rate that makes your investment's net present value zero — more useful for comparing investments with different cash flow patterns over time.
Regular contributions add their own compounding growth on top of your initial lump sum, using the annuity formula PMT × ((1+i)^N - 1) / i — each contribution has less time to compound than the very first one, but the combined effect can significantly boost your total future value.
It's the point at which your cumulative cash flow turns positive — in other words, when you've recovered your original investment. It's a simple way to gauge risk: a shorter payback period generally means less time your capital is exposed before breaking even.
No — this calculates the mathematics of compounding, ROI, IRR, and payback based on the rate and cash flows you provide. It doesn't recommend specific investments or assess risk suitability; consult a qualified financial advisor for personal investment advice.