How the debt budget calculator works
The waterfall, and why order matters
Every surplus dollar has one job: earn the highest guaranteed-or-free return available. That orders the waterfall: mini emergency fund (prevents 24% borrowing), employer match (instant 50–100%), debt above ~7–8% (guaranteed), full emergency fund, then investing. Most people run steps 2 and 4 and skip 1 and 3 — the calculator makes the order explicit so the dollars cannot argue.
The mini-fund insight
A full 6-month fund before debt payoff delays progress by a year or more — and is unnecessary: the fund's job is preventing new borrowing. One month of essentials does that job for a fifth of the capital, freeing the surplus to kill the 24% interest that dwarfs every savings rate in the plan.
Re-run monthly, not annually
Balances fall, rates change, matches get maxed — the optimal allocation migrates. The waterfall is a five-minute monthly re-run (or a set-and-forget automation that mirrors it), not a New Year resolution. The budget lives because it is arithmetic, and arithmetic is cheap to redo.