Every vehicle owner eventually faces the dilemma of whether to keep pouring money into an aging car or to buy a newer one. Repairs may start small, but as components wear out, bills mount quickly. At the same time, purchasing another car introduces depreciation and maintenance costs that may outstrip the price of periodic fixes. This calculator transforms that gut feeling into tangible numbers by comparing the cost of continued repairs with the expense of buying and maintaining a replacement vehicle over a chosen time horizon.
The form above requests five inputs. Annual repair cost represents how much you expect to spend each year to keep your current car running. Replacement purchase price captures the cost of the newer car you might buy. Because vehicles lose value over time, the annual depreciation rate expresses how much of the purchase price disappears each year as a percentage. Maintenance cost for the replacement car estimates routine service beyond repairs, such as oil changes and tire rotations. Finally, the ownership horizon indicates how long you plan to own either car, allowing costs to be calculated over the same period for a fair comparison.
Mathematically, the cost of keeping the current car is straightforward: , where is annual repair cost and is years. The replacement car cost is a bit more involved. It includes depreciation, represented as , with as purchase price and as the decimal depreciation rate. Adding maintenance yields total replacement cost , where is annual maintenance. Comparing and reveals the financially wiser option.
Suppose your current sedan requires about $1,200 in repairs each year. A reliable used car costs $15,000 and depreciates 15% annually. Maintenance on the newer vehicle is estimated at $400 per year. Over five years, keeping the old car totals $6,000 in repairs. The replacement car's value drops to roughly $7,464 after five years, meaning $7,536 of depreciation plus $2,000 in maintenance for a total of $9,536. In this scenario, repairing the current car saves $3,536 over the chosen period.
The table below expands the example, demonstrating how different repair costs and depreciation rates influence the decision over a five-year horizon with a $15,000 purchase price and $400 annual maintenance.
| Annual Repair Cost | Depreciation Rate | Keep Cost | Replace Cost | Cheaper Option |
|---|---|---|---|---|
| $800 | 10% | $4,000 | $8,725 | Keep |
| $1,200 | 15% | $6,000 | $9,536 | Keep |
| $2,000 | 20% | $10,000 | $11,836 | Keep |
| $3,000 | 20% | $15,000 | $11,836 | Replace |
While numbers provide clarity, qualitative factors remain important. A newer car may offer safety features, improved fuel economy, and peace of mind that are not captured in repair bills. Conversely, sentimental attachment or knowledge of a vehicle's history may outweigh the appeal of a replacement. This calculator isolates the financial component so you can layer these subjective considerations on top.
Limitations include the assumption of constant annual repair costs. In reality, repairs might escalate as a car ages or fluctuate unpredictably. Depreciation is modeled as a simple percentage, but market conditions can cause values to drop faster or slower. Insurance premiums and financing costs for a replacement car are omitted, though they can influence the final decision. The tool also presumes you pay cash for repairs and purchases; interest on loans would alter the comparison.
If you want broader context on vehicle expenses, visit the used car reliability cost estimator to gauge potential repair frequency or the car cost of ownership calculator for a full picture including fuel and insurance. These resources complement the repair versus replace analysis provided here.
Ultimately, every car reaches a tipping point where repairs exceed value. By quantifying both options, this calculator helps you identify that moment before frustration or a catastrophic breakdown forces an emergency decision. Regularly revisiting the numbers as repair bills arrive or as market prices shift keeps your transportation strategy grounded in data, ensuring your ride remains as dependable on your wallet as it is on the road.