Car-Buy Opportunity Cost

"What does my next car decision really cost over 30 years?"

You cannot quit a toxic job if you have a $1,000 monthly car payment.

— Debugging Your Personal Finance, Chapter 6

Expensive car (financed)

Cheap alternative (paid cash)

Price ($)

Investment assumptions

Numbers shown are terminal wealth at the horizon from investing the cash flows each strategy frees up, modeling a single purchase held for the full horizon. The book's own 30-year worked example instead has each buyer replace their car every decade (three purchase cycles), so plugging in the book's exact prices here will not reproduce its cited totals — use this calculator to test your own one-time decision, not to re-derive the book's figures. Lower numbers in the Debtor / Saver columns = more opportunity cost. The Strategist invests the upfront price delta plus the loan-payment-equivalent stream.

From Chapter 6 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.