A field-by-field guide to Rent vs Buy: 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 net worth path and break-even year meaningful.
This guide helps you define home price, downpayment, interest rate, and rent 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: home price, downpayment, interest rate, rent, and investment return.
Be consistent about units (monthly vs annual) and scope (include fees/taxes if they exist in real life).
Compare outputs like net worth path and break-even year across scenarios instead of trusting one number.
If the decision changes under downside assumptions, build a buffer or revise the plan.