Annual returns are treated as effective annual rates. Monthly rate = (1 + annual return / 100)^(1/12) − 1. SIP contributions are made at the end of each month. Step-up contributions increase after every 12 payments. A lump sum is invested at the start.

The portfolio grows or falls at the assumed monthly rate before each month-end withdrawal. Withdrawals are fixed in nominal rupees and stop when funds run out. The final withdrawal may be smaller than requested.

An SWP is a withdrawal method, not a guaranteed-income product. Withdrawals can include your own principal. Taxes depend on the investment and transaction circumstances and are excluded.

Annual expenses at the target age are estimated using the entered inflation rate. Target portfolio = those annual expenses divided by the assumed initial annual withdrawal rate.

Existing investments and fixed monthly contributions are projected to the target age. This is a target-sizing model: it does not simulate retirement longevity, post-retirement returns, sequence risk, taxes or changes in spending. The default withdrawal rate is illustrative, not a universally safe rate.

CAGR = (ending value / starting value)^(1 / years) − 1. It measures annualized growth between two values and assumes no intermediate contributions or withdrawals.

XIRR solves the annual rate at which dated cash flows have a net present value of zero, using actual elapsed days divided by 365. Same-date flows are combined.

This implementation accepts conventional cash flows: after sorting and combining dates, negative flows must precede positive flows. Multiple switches between negative and positive flows are blocked because multiple or ambiguous IRRs can result. A numerical solution is not guaranteed for every dataset.

No. Growth models use constant assumed returns and do not model market volatility. Fees, taxes and inflation are excluded except for the explicit expense-inflation assumption in FIRE. Defaults are examples, not forecasts or recommendations.