Spending and goals

Spending splits into essential costs (housing, food, medical, insurance) and discretionary ones (travel, dining, hobbies) — the difference matters because only discretionary spending gets trimmed in a bad market year.

The spending guardrail: after a year with a negative real market return, next year's discretionary spending is automatically halved. Essential spending is never cut, no matter how the market does. A run in your results can still count as a "success" even if the guardrail trimmed discretionary spending along the way — see "What chance of success means" for the separate figure that tracks how often spending was never cut at all.

Retirement spending itself can follow one of three modes: same as today (unchanged), an override (one different flat monthly amount for all of retirement), or by phase — a "smile curve" that's higher early in retirement, dips in the middle, and rises again later for healthcare costs, each phase with its own age cutoff and multiplier.

College costs assume $28,000/year at a public school or $60,000/year at private, for four years starting at age 18, and are drawn only from that kid's own 529 account. "Target funded %" (100% by default) sets how much of that cost the plan should cover; the rest is assumed to come from somewhere else, at no cost to the plan.

One-time expenses are taken directly from your accounts in the single year you specify. Legacy target and expected inheritance are also captured here.