Plan fixed monthly investment withdrawals

The monthly return is (1 + annual return/100)^(1/12) − 1. At each month’s end, growth is calculated on the opening balance, rounded to the nearest cent and added before the withdrawal. The first withdrawal is dated one month after the projection start date. Calendar dates keep the starting day where possible and clamp it to the last day of shorter months.

A withdrawal cannot exceed the available balance. With 2,500 initially, a requested monthly withdrawal of 1,000 and zero return, payments are 1,000, 1,000 and 500. The balance reaches zero in month 3 and later months are omitted. A zero starting balance is depleted at the start. No depletion within the horizon does not mean the balance will last forever.

This is a deterministic nominal-money projection, not a forecast of investment performance or a safe-withdrawal recommendation. The return is constant and excludes market volatility, fees, taxes and inflation. Changing the display currency does not convert exchange rates. Starting balance and requested withdrawals use decimal cent rounding before calculation: 1.005 becomes 1.01. Monthly growth is rounded to the nearest cent, with exact half-cent ties toward positive infinity, so a negative half-cent rounds toward zero. Every CSV row uses the same cent-rounded ledger as the summary.

Amounts must be between zero and one trillion, with an effective annual return from −100% to 100% and a horizon from 1 to 1,200 whole months. A −100% annual return is modeled as a complete loss before the first payment. An excessively growing balance or an unsafe numeric total is rejected. The on-page table previews up to 120 rows; the CSV contains every calculated month, stopping at depletion.