Car Total Cost of Ownership Calculator

Related Calculators

Table of contents

• How to use
• Common mistakes
• Definitions
• Methodology
• Limitations & assumptions
• Sources

Total cost to own: All included costs during the years you keep the car, minus the Expected resale value ($). Total cost of ownership is meant to look past the purchase price and include operating costs too [1].

Value lost or gained: Purchase price ($) minus Expected resale value ($). A positive number means the car lost value. A negative number means the car is expected to be worth more than you paid.

Fuel economy (mpg): Miles per gallon. Higher mpg means the car travels farther on each gallon of gas.

Average cost per mile: Total cost to own divided by all miles driven during the ownership period.

Loan APR (percent): The yearly borrowing rate used to estimate loan interest during the time you own the car.

Loan term (months): The full length of the auto loan, even if you sell the car before the loan ends.

Maintenance and tires (cents per mile): A per-mile estimate for routine service and tire wear, separate from Repairs ($ per year).

Mistake: Using the odometer reading for Miles driven each year.
Fix: Enter only the miles you expect to drive in one year, such as 12000.

Mistake: Treating Average cost per month as the loan payment.
Fix: Use Average cost per month as the full ownership average, including value lost, fuel, insurance, upkeep, fees, and any Loan interest included.

Mistake: Entering Sales tax rate (percent) when Purchase price ($) already includes tax.
Fix: Leave Sales tax rate (percent) at 0 if the Purchase price ($) is already an out-the-door price.

Mistake: Leaving Loan amount ($) above 0 but entering 0 or a blank Loan term (months).
Fix: Enter the full Loan term (months), or set Loan amount ($) to 0 for a cash purchase.

Mistake: Assuming Value lost or gained must always be positive.
Fix: If Expected resale value ($) is higher than Purchase price ($), the calculator keeps a negative Value lost or gained because the car is expected to gain value.

Mistake: Forgetting regular local costs in Registration, inspection, and local fees ($ per year) or Parking and tolls ($ per month).
Fix: Add recurring fees, permits, garage costs, and toll routes if they are part of owning that car.

• This is an estimate, not a dealer quote, tax bill, insurance quote, or loan disclosure.
• Fuel cost assumes one Fuel economy (mpg), one Gas price ($ per gallon), and gasoline-style miles per gallon. It does not model electric charging or mixed fuel types.
• Expected resale value ($) is a user estimate. Market prices, mileage, condition, accidents, demand, and trade-in offers can change the real resale amount.
• Insurance ($ per year), Repairs ($ per year), and Registration, inspection, and local fees ($ per year) can vary a lot by driver, ZIP code, state, car, and coverage choice.
• Loan interest included uses a fixed-rate monthly loan formula and counts interest only for the months you own the car, up to the Loan term (months).
• Average cost per mile is N/A when Miles driven each year is 0, because cost per mile needs miles above 0.
• A negative Total cost to own is possible if the expected resale gain is larger than the included costs; the calculator keeps that signed result instead of forcing it to 0.

How the calculator adds the costs

The calculator estimates car total cost of ownership over the years you plan to keep the car. It adds value lost or gained, fuel, insurance, maintenance, repairs, taxes, recurring fees, parking and tolls, and loan interest, then uses the same total for monthly, yearly, and per-mile averages.

total_miles = annual_miles * ownership_years

depreciation_cost = purchase_price - resale_value

fuel_cost = (annual_miles / fuel_efficiency_mpg) * fuel_price * ownership_years

insurance_cost = annual_insurance * ownership_years

sales_tax_cost = purchase_price * (sales_tax_rate / 100)

maintenance_and_repairs_cost = (annual_miles * (maintenance_cents_per_mile / 100) * ownership_years) + (annual_repairs * ownership_years)

taxes_and_fees_cost = sales_tax_cost + (annual_fees * ownership_years)

parking_tolls_cost = parking_tolls_monthly * 12 * ownership_years

Loan interest method

If Loan amount ($) is 0, Loan interest included is 0. If Loan amount ($) is above 0, the calculator uses a standard fixed monthly payment formula. It counts interest for the smaller of the months owned and the Loan term (months), so selling before payoff counts only the interest paid during ownership.

monthly_rate = loan_apr / 100 / 12

loan_payment = loan_amount * monthly_rate / (1 - (1 + monthly_rate)^(-loan_term_months))

months_counted = min(ownership_years * 12, loan_term_months)

finance_interest_cost = payments_during_ownership - principal_paid_during_ownership

If Loan APR (percent) is 0, the calculator treats the loan as no-interest and sets Loan interest included to 0.

Final outputs

total_cost = depreciation_cost + fuel_cost + insurance_cost + maintenance_and_repairs_cost + taxes_and_fees_cost + parking_tolls_cost + finance_interest_cost

average_monthly_cost = total_cost / (ownership_years * 12)

average_annual_cost = total_cost / ownership_years

cost_per_mile = total_cost / total_miles

If total_miles is 0, Average cost per mile is shown as N/A because dividing by zero miles would not be meaningful.

Mini-example

For a car with Purchase price ($) of 30000, Expected resale value ($) of 15000, 5 years owned, 12000 miles per year, 28 mpg, $3.50 gas, $1694 yearly insurance, 11.04 cents per mile maintenance, $300 yearly repairs, $300 yearly fees, 6 percent sales tax, a $25000 loan at 6 percent for 60 months, and no parking or tolls, the calculator gets $7500 fuel cost, $15000 value lost, $8470 insurance cost, $8124 maintenance, tires, and repairs, $3300 taxes and recurring fees, and about $3999.20 loan interest.

total_cost = 15000 + 7500 + 8470 + 8124 + 3300 + 0 + 3999.20 = 46393.20

That same example gives an Average cost per month of about $773.22 and an Average cost per mile of about $0.77 over 60000 miles.