Investment Planner

This planner simulates two funds side by side, year by year, from year 0 through the plan-end year, across two phases — accumulation, then drawdown. It is a planning aid, not investment advice — it ignores taxes, fees and inflation.

Leaver fund

A one-shot investment made at year 0. It grows quietly until its exit year, then matures either to a fixed multiple of the initial amount (e.g. 3x) or by compounding at an annual % rate for the number of years held. At exit, the proceeds are either paid out to you as cash, or — if "Reinvest leaver proceeds" is on and the exit happens at or before plan end — rolled directly into the yielder fund's balance, whichever phase it's currently in.

Accumulation phase (year 0 or 1 through drawdown start − 1)

You contribute a fixed amount every year, starting year 1 (or year 0 if you enable that toggle), for however many years you set under Contribution years. Once that count is reached, contributions stop — but the balance keeps compounding normally for the rest of the accumulation phase, it just stops receiving new cash. If you set more contribution years than there's room for before drawdown starts, the window is simply capped at the last accumulation year (drawdown start − 1) — contributions never spill into the drawdown phase. Throughout, the running balance earns an annual return: with "Reinvest yield" on, that return compounds into the balance; with it off, the return is paid out to you as cash each year and the balance grows only from contributions (and any reinvested leaver proceeds). No withdrawals happen in this phase.

Drawdown phase (drawdown start year through plan-end year)

Contributions stop. Each year, Redemption % of the current balance is withdrawn first and paid to you as cash income; the return for that year is then applied to whatever balance remains, compounding it automatically (the "Reinvest yield" toggle only governs the accumulation phase — in drawdown, yield always stays in the balance to fund future withdrawals). If the leaver exits mid-drawdown with reinvestment on, its proceeds land in the balance before that year's withdrawal is calculated.

Plan-end liquidation

At the plan-end year, the normal drawdown withdrawal and yield still happen first, then whatever balance remains is liquidated in full as one final cash inflow and the balance drops to zero — unless "Perpetual" is on (see below), in which case no liquidation ever happens.

Perpetual mode

Turning on "Perpetual (never ends)" removes the plan-end liquidation entirely — the drawdown withdrawals continue as an ongoing income stream forever, and the balance is never force-liquidated. The plan-end year field becomes a pure display horizon: the ledger and chart still stop there, and a banner above shows the ongoing balance at that year plus whether it's still growing or shrinking. Because nothing is ever liquidated, "Total returned" / "Net profit" / "MOIC" reflect only the cumulative income received through the display horizon, not a lifetime total — the summary card labels this explicitly. IRR still needs to see the whole stream to mean anything, so internally it's computed against a 200-year continuation of the same withdrawal pattern with no terminal payout (a perpetuity approximation — at any realistic rate the far-future years are discounted to almost nothing, so 200 years is indistinguishable from forever). If no rate can be found that balances the stream, IRR shows "n/a" exactly as in the ordinary case.

Dividend column

Shows the yield the yielder balance produces that year (balance × annual return, realized at year-end) for every single year — whether it's reinvested, paid out, or automatically compounded during drawdown — so you can see what the fund is earning independent of the cash-flow columns.

Per-year order of operations

Accumulation year: (1) yielder contribution is added, (2) leaver proceeds are added to the balance if this is the exit year and reinvestment is on, (3) that year's interest is applied to the resulting balance (so newly reinvested money earns a return the same year it lands). Drawdown year: (1) leaver proceeds are added if this is the exit year and reinvestment is on, (2) the redemption-% withdrawal is taken from the current balance and paid out as cash, (3) that year's interest is applied to the remaining balance and always compounds in, (4) if this is the plan-end year, the entire remaining balance is paid out and zeroed.

Contribution timing comparison

The comparison card above always computes the full plan two ways — contributions starting year 1 vs. starting year 0 — so you can see the effect of that one extra year of compounding on IRR, totals and MOIC without changing any other input. The detailed ledger and chart below follow whichever one the toggle currently selects.

Contribution years comparison chart

This bar chart sweeps Contribution years from 0 up to drawdown start − 1 (any higher and the result is identical to the capped maximum, so there's no point sweeping past it), re-running the full plan at every value with everything else held at your current settings. Switch the metric selector to compare IRR, total returned, net profit or MOIC across that range, and the bar matching your current "Contribution years" value is highlighted so you can see exactly where you sit on the curve.

MOIC & IRR

MOIC (multiple on invested capital) is simply total cash returned divided by total cash invested. IRR is the annualized rate that makes the net present value of every yearly cash flow (in, out, and net) equal to zero — found numerically via bisection, so it properly accounts for when money moves, not just how much. If a scenario has no negative cash flow (nothing invested) or no positive cash flow (nothing ever returned), IRR shows "n/a".