A field-by-field guide to SWP Calculator: what to include, what to exclude, and how to avoid unit mistakes.
Inputs are the only “truth” the model sees. Clean input definitions make outputs like ending corpus and depletion estimate meaningful.
This guide helps you define starting corpus, withdrawal, expected return, and years so the calculator reflects your real scenario—not a spreadsheet fantasy.
Before typing, decide whether values are monthly, annual, per-unit, or per-order. Most errors come from mixing these silently.
If you’re unsure, re-run with a simpler scenario and confirm the output direction.
Key inputs: starting corpus, withdrawal, expected return, and years.
Be consistent about units (monthly vs annual) and scope (include fees/taxes if they exist in real life).
Compare outputs like ending corpus and depletion estimate across scenarios instead of trusting one number.
If the decision changes under downside assumptions, build a buffer or revise the plan.