How it works
The repair-or-replace decision is a bet, and this calculator prices the odds honestly rather than reacting to the latest scary invoice. Keeping a car has an expected annual cost: routine repair and maintenance spending plus the probability-weighted chance of a major failure — on defaults, $1,400 of routine work plus a 35% shot at a $2,400 bill equals roughly $2,240 a year, or $8,960 across a four-year horizon. That expectation competes against the net cost of upgrading: replacement price minus your trade-in, $11,500 here. The verdict line names the cheaper path and the margin, while the break-even figure shows how bad repair luck must get before replacing wins outright. Two disciplines make the numbers trustworthy. First, use trailing reality for routine spend — last year's actual card statements, not optimism. Second, remember the gamble does not pause while you save: the schedule's crossover column shows cumulative repairs overtaking the upgrade cost in year six if you keep waiting, which is precisely the trap of 'one more year' reasoning. Emotional factors — safety features, reliability anxiety, a baby arriving — are legitimate tiebreakers; this tool just ensures the financial tiebreaker is priced correctly before it breaks the tie.
Formula
Expected/yr = routine + (odds% × major bill) | Keep(h) = expected × years | Upgrade = price − trade-in | winner = lower total over the horizon
Tips
- Use last year's real repair invoices for the routine line — memory lowballs by half.
- Raise the odds estimate sharply after 100–150k miles; transmission and timing-chain risk clusters live there.
- Compare against a certified used car, not new — the net-upgrade line shrinks fastest there.
- Get one diagnostic quote before deciding; a $150 inspection often re-prices a $2,000 fear.
- If upgrading wins, fund it with a sinking fund before the current car dies on its own schedule.
Frequently asked questions
- At what point is a car not worth repairing?
- When expected annual repair economics beat the net cost of a replacement. Here, repairs averaging $2,240 a year against an $11,500 net upgrade cross over in year six — meaning the sixth consecutive year of this pace effectively buys the next car anyway. Single big bills deserve context: one $2,400 fix still beats $11,500 unless the pattern repeats.
- How much should I budget for car repairs per year?
- A common rule is 1–2% of the car's value plus oil changes and tires, but trailing reality is better: pull twelve months of statements. This calculator's default profile — $1,400 routine plus risk-weighted majors — lands near $2,240 expected, typical for a 10-year-old vehicle driven normally.
- Is it cheaper to keep an old car?
- Usually yes until the maintenance curve steepens. Depreciation is the largest ownership cost, and an old paid-off car skips it entirely — which is why keeping wins by $2,540 on these defaults. The advantage erodes as major-repair probability climbs past roughly 35–40% a year or routine spend drifts toward $3,000.
- Should I finance a car or keep fixing my old one?
- Price both over the same horizon. A $16,000 used replacement financed at 7% costs about $384 a month for four years — comparable to the $747 monthly expected cost of heavy-repair years. If your old car's expected spend is far below the payment, keep it and bank the difference toward a future cash purchase.
- How do I know if my car will need major repairs soon?
- Warning clusters matter more than mileage alone: age past ten years, mileage past 120k, fluid leaks, irregular shifts or idle, and a repair history that is accelerating. A pre-decision inspection ($100–$200) converts vague dread into specific quotes you can feed into the odds and bill fields above.