What is the calculation method for car depreciation?

[HazelRose]

Vehicle depreciation calculation methods are generally divided into two categories: one is the average calculation method (straight-line method and units of production method), and the other is the accelerated depreciation method (double declining balance method and sum-of-the-years'-digits method). The formula for the straight-line method: Annual depreciation equals the original value divided by the estimated useful life. The formula for the units of production method: Depreciation is calculated based on the mileage driven, with the depreciation amount equal to the original value (miles already driven divided by estimated total mileage). The formula for the double declining balance method: The depreciation percentage equals 2 divided by the estimated useful life. The annual depreciation amount equals the value at the beginning of the year multiplied by the depreciation percentage. In the last two years of the estimated useful life, the remaining value is evenly distributed. The formula for the sum-of-the-years'-digits method: The depreciation amount equals the original value multiplied by (remaining useful life divided by the sum of the years' digits).

[KarterAnn]

Having driven for over a decade and handled seven or eight used cars, depreciation is actually quite a relatable topic in daily life. For regular family cars, I estimate depreciation using the 'half in three years' rule. For example, a new car worth 200,000 yuan would be worth about 100,000 to 120,000 yuan after three years. The condition of the car significantly impacts its price: if it's been in an accident, the value drops by at least another 30%, while full maintenance at a 4S dealership can add 5,000 to 10,000 yuan to the resale value. Japanese cars hold their value the best, while German cars fare well in the first three years but depreciate faster later due to higher maintenance costs. I check the prices of the same models on used car platforms every year to get a good sense of the market. When calculating depreciation, don't just focus on the age of the car—details like the number of ownership transfers, tire wear, and the condition of the interior can all add significant value.

[LucilleDella]

After being in the used car circle for a while, I noticed that people often use the '1510 rule' for rough estimates. The first year sees a 15% depreciation—for example, a 300,000-yuan car drops to 250,000 yuan. After that, it loses 10% annually, and by the fifth year, it’s basically worth half. When actually buying a car, three main factors come into play: brand resale value (Toyota and Honda usually hold 5% more value than French or American brands), mileage (every additional 20,000 km over 100,000 km cuts 5,000 yuan), and maintenance records (engine or transmission repairs slash the price by half). The most practical tip is to check recent transaction prices on your phone—the average price for the same model on Guazi Used Car plus 2,000 yuan serves as the reference line for buying.

[HavenLee]

Last time I sold my car, I specifically researched depreciation calculation methods, and now the three common approaches are quite practical. The most hassle-free is the straight-line method: assuming a 10-year lifespan, it depreciates 10% each year. But I personally prefer the units-of-production method, spreading the total price of 300,000 over 200,000 kilometers, with each kilometer driven consuming 1.5 yuan, which feels fairer for high-mileage car owners. The double-declining balance method is more professional, allowing 40% depreciation in the first two years, making it suitable for those who change cars frequently. Regardless of the method used, remember that odometer tampering can cause residual value to plummet, while a complete maintenance record can increase the final transaction price by about 8%.