Car Ownership Cost Calculator
Estimate the true annual cost of owning a car — insurance, fuel, depreciation and cost per mile
快速情境範本
點擊套用常見車款的典型費用，快速開始計算
車輛基本資訊
油耗
固定費用
年里程
計算結果
下一步
支出佔比分析
長期持有成本分析
About the Car Ownership Cost Calculator
The Car Ownership Cost Calculator is a free online tool that helps you accurately estimate the true cost of buying and owning a car. Many people only look at the sticker price when buying, but overlook the ongoing cost of ownership. This calculator brings together the major expense items so you get a full picture of what a car really costs each year.
Calculator Features
- Depreciation calculation: uses a declining-balance method (about 22% in year 1, 13% in year 2, tapering off), which better reflects the real used-car market
- Maintenance estimate: annual maintenance based on service interval and cost per visit, with an automatic vehicle-age adjustment factor (older cars cost more to maintain)
- Tire replacement cost: the cost of replacing tires over their lifespan
- Battery cost: the annualized cost of battery replacement
- Fuel cost: fuel spending based on fuel economy and annual mileage
- Insurance: annual liability and comprehensive premiums
- Fixed costs: registration, parking, car wash and more
- Visual chart: a pie chart clearly shows how each expense stacks up
- PDF report export: download a complete cost-analysis report
- Share function: share your results with one click
How the calculation works
Why use declining-balance depreciation?
Real-world car depreciation isn't a flat amount each year. Based on used-car market data, a new car loses value fastest in its first year (roughly 20-25%), then depreciation slows year over year. This calculator uses a more realistic declining-balance model so you can gauge actual value loss more accurately.
Why does vehicle age affect maintenance cost?
A car under warranty (years 1-3) usually costs less to maintain, but once out of warranty (year 4 and beyond) parts wear out and failure rates climb, so maintenance costs rise. Based on the ownership length you set, this calculator automatically adjusts the maintenance factor (a 10-year-old car runs roughly 85% higher), bringing the estimate closer to real ownership costs.
Why calculate the cost of owning a car?
On average, annual ownership costs run about 10-15% of a car's price. For a $30,000 car, that can mean $3,000-$4,500 a year — and that's before depreciation. With this calculator you can:
- Assess whether a car fits your budget before you buy
- Compare ownership costs across different models
- Plan your monthly car-related budget
- Understand the true cost of every mile you drive
- Make a smarter buying decision
How to use this calculator
- Enter your car price and how long you plan to keep it
- Fill in maintenance details (service interval, cost per visit)
- Enter tire and battery replacement intervals and prices
- Enter your fuel economy and current fuel price
- Enter fixed costs (registration, insurance, parking, etc.)
- Enter your expected annual mileage
- The tool instantly calculates your total annual cost and cost per mile
All data is saved automatically in your browser and reloads next time you visit. You can reset to defaults at any time, or use the share function to send your results to someone else.
Frequently Asked Questions (FAQ)
Q: Are the results accurate?
This calculator provides estimates. Actual costs vary by driving habits, vehicle condition and region. For the most accurate result, enter values that match your own situation.
Q: Is my data stored?
Your data is stored only locally in your browser (LocalStorage) and is never uploaded to a server, so your privacy is fully protected.
Q: Can I use it for an electric vehicle?
Yes. For an EV, enter efficiency as miles per kWh and the fuel price as your electricity rate ($/kWh); the other expense items stay the same. A dedicated EV version may come later.
Q: How do I share my results?
Click the Share button and the tool generates a URL containing all your inputs and copies it to your clipboard. Send that link to someone and they'll see the same results when they open it.
Q: Why does the annual cost go up when I set a longer ownership period?
Because the calculator uses a more realistic cost model:
- Age adjustment factor: older cars cost more to maintain. Under warranty (years 1-3) maintenance is normal (factor 1.0), but a 10-year-old car can run 1.85x due to aging parts, higher failure rates and more frequent repairs.
- Declining-balance depreciation: although depreciation is front-loaded (more early, less later), spreading it over a longer ownership period lowers the average annual depreciation.
- The bottom line: in the first 3 years a car has lower annual costs thanks to warranty coverage, new parts and fewer breakdowns; but as it ages, depreciation slows while maintenance and repair costs climb, so total annual cost can actually rise.
Tip: if you plan to keep a car long term (10+ years), budget for higher maintenance costs, especially in years 6-10 after the warranty ends.
Q: How does the depreciation calculation work?
This calculator uses declining-balance depreciation to model a realistic used-car depreciation curve:
- Year 1: about 22% (a new car loses value the moment it's driven off the lot)
- Year 2: about 13%
- Year 3: about 11%
- Years 4-5: 8-9% per year
- Years 6-10: 5-7% per year
- After year 10: about 4% per year
For example, a $30,000 car depreciates about $6,600 in year 1, about $3,050 in year 2, and only about $780 in year 10 — more realistic than straight-line depreciation (a flat $3,000 a year).
