Car: Buy, Lease or Keep? The true cost per mile of each

Your cars

Quick start

These give you a full answer. Everything else uses typical assumptions; open the sections below to fine-tune.

Years to compare

yrs

Miles a year

Your car's value

Repairs a year

What it would sell or trade for, and what you spend on repairs and maintenance a year now. Buying trades it in; leasing sells it.

New car's price negotiated, before tax

Loan APR

Loan term

Down payment cash, plus the trade-in

Lease money factor

Lease term

Lease residual

Sales tax

Keeping your car

Repairs rise by /yr, on top of inflation

Older cars need more. 5–10% a year is a common planning range.

A major repair

In year (0 = none)

It loses value by /yr

Buying

The car is

Value lost, year 1

Then, per year

Value lost /yr

Dealer doc fee

Title, registration

Charged once for each car you buy or lease.

My state taxes the price after the trade-in

Most states do. A few charge sales tax on the full price.

Final assembly in the US

Needed for the car loan interest deduction. The window sticker shows the final assembly point.

Leasing

Lease payment

Quoted payment /mo, before tax

Capitalized cost

Sticker price

Enter 0 in either to use the new car's price. The residual is a share of the sticker price.

Cash down on the lease cap cost reduction

Acquisition fee

Disposition fee

The acquisition fee is added to the capitalized cost. The disposition fee is charged when you hand the car back.

Miles a year

Each extra mile

Your state taxes a lease

When a lease ends

Purchase option fee

Paid in cash with sales tax on the residual. The car is then worth what any car its age would be.

Fuel, insurance and upkeep

Gas price per gallon, today

Your car's MPG

New car's MPG

Insurance, per year from your quotes

Keep

Buy

Lease lessors set minimum coverage

Upkeep a year

Flat for (years)

Maintenance and tires on the bought or leased car. After the warranty years it rises at the repair rate above. A used car rises from year 1.

Money and taxes

Return on cash you don't spend /yr, after tax

What a down payment or a car's value could earn instead. 4% is a typical high-yield savings rate; 0 compares cash alone.

Inflation /yr, for today's dollars

Count the car loan interest deduction

2025 to 2028 only, for a new car with final assembly in the US. You don't need to itemize.

Filing status

Modified AGI

Tax bracket

Net cost so far, year by year

Keep your car Buy Lease

Cash paid each year and the net cost so far for each option
Year	Paid, keep	Paid, buy	Paid, lease	Bought car's value	Loan left	Net, keep	Net, buy	Net, lease

"Paid" is cash out that year before the return on cash and inflation. "Net" is the cost so far in today's dollars, after the value of the car you hold.

Where the money goes

Total cost of each option by category over the whole period
Over	Keep	Buy	Lease

Cash amounts are as paid, before the return on cash and inflation. Negative amounts come back to you.

What could change the answer

Net cost of each option under each scenario
Scenario	Keep	Buy	Lease	Cheapest

Net cost over the whole period, in today's dollars.

What this leaves out

EV credits. The federal credits for new and used electric cars ended for cars bought after September 30, 2025, so there is none to count in 2026. Some states and utilities still offer rebates: subtract any from the price.
Business use. Mileage or depreciation deductions for a car used for work aren't modeled.
Buying out a lease early, or ending one early. The end-of-lease buyout is an option under Leasing.
Gap insurance and extended warranties. Add their cost to the insurance or upkeep inputs if you'd buy them.
Credit-score effects of a new loan or lease, and the time and hassle of selling a car.
Yearly registration and property taxes on the car, which in many states are based on its value.