Pay Cash or Finance a Car Calculator
The car, your cash, the loan, and what the cash would earn
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Educational estimate only. Confirm the assumptions, current rules, fees, and rounding that apply to your situation before making a decision.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the out-the-door price, the cash and savings you have, and your essential monthly expenses. The expenses measure how long what is left would last in an emergency.
- 02
Enter the loan you have been offered: the down payment you would make, the APR and the term.
- 03
Enter the return you expect on cash you keep, and the tax on that return. Use a savings rate if the money would stay in the bank, or a long-run portfolio return if you would invest it, and remember that a return is not guaranteed.
- 04
Enter your marginal tax rate. The page figures the car loan interest deduction in parallel, for the case where the car is new, US-assembled and bought for personal use.
- 05
Read which path finishes ahead and by how much, then the return the cash must beat, then the table of where both paths finish at returns from 0% to 10%.
Formula
Loan = price − down payment, and payment = the amortizing payment on that loan. After-tax monthly return r = expected return × (1 − tax on the return) ÷ 12. Pay-cash path: invest the loan payment every month for the term, ending with the future value of those deposits at r. Finance path: keep the loan amount invested, ending with loan × (1 + r) raised to the number of months. The better choice is the larger ending balance. With the deduction, each year's interest inside the 2025-2028 window, up to the $10,000 cap, times your marginal rate is added to the finance path when it is saved. The paths tie when the after-tax return equals the loan's APR, so the break-even return before tax = APR ÷ (1 − tax on the return).
Example
A $38,000 car, $55,000 of savings and $4,500 of monthly expenses. Financing puts $7,600 down and borrows $30,400 at 6.35% over 60 months: $593 a month and $5,161 of interest. The kept cash is assumed to earn 5% taxed at 15%, or 4.25% after tax. Paying cash and investing $593 a month ends at $39,544; financing and keeping $30,400 invested ends at $37,584, so paying cash is $1,960 ahead, and the cash would need 7.47% before tax to tie. If the car qualifies for the deduction, a 22% rate saves $771 over the first 27 payments, financing ends at $38,478, and paying cash is still $1,066 ahead with a break-even of 6.34%. Paying cash leaves $17,000 in savings, 3.8 months of expenses; financing leaves $47,400.
Definitions
- Opportunity cost
- What money could have earned in its next-best use. Cash spent on a car gives up the return it would have made if kept invested.
- After-tax return
- The return left once tax on it is paid. It is the figure to set against a loan rate, not the headline return.
- Break-even return
- The return at which paying cash and financing finish level. Without the deduction it is the loan's APR divided by one minus the tax rate on the return.
- Emergency cushion
- Savings you can reach quickly for an unexpected bill, often measured in months of essential expenses.
- Car loan interest deduction
- A federal deduction for 2025-2028 of up to $10,000 a year of interest on a loan for a new, US-assembled personal vehicle, phased out above $100,000 of MAGI ($200,000 joint).
Good to know
The comparison most people get wrong
The usual way to decide is to set the loan's total interest against what the cash would earn if you kept it, and pick the smaller number. That comparison is lopsided. It counts the loan's interest across every payment while treating the cash as a lump sum that sits untouched, and it ignores the monthly payments that financing takes out of your income and paying cash does not. A fair test keeps the money leaving your household the same on both paths. On this page both paths put the down payment in on day one. Financing then keeps the rest of the price invested and pays the loan from income. Paying cash spends that money on the car, and each month invests the loan payment it no longer owes. After the last payment each path holds a portfolio, and the larger one wins. On the default figures, a $38,000 car with $7,600 down leaves $30,400 to finance at 6.35% over 60 months: $593 a month and $5,161 of interest. The kept cash is assumed to earn 5% a year, taxed at 15%, so 4.25% after tax. Paying cash and investing $593 a month ends at $39,544. Financing and keeping $30,400 invested ends at $37,584. Paying cash finishes $1,960 ahead. Set up this way, the answer rests on one comparison: the after-tax return against the loan's APR. When they are equal the two paths tie exactly, because investing the payments at the loan's own rate rebuilds the loan balance. Here the cash would have to earn 7.47% before tax, which is 6.35% after a 15% tax. The table shows the answer flipping between 6% and 8%.
Certainty against expectation
The two sides of this comparison are not the same kind of number. The loan's rate is written into a contract, and every payment is known on the day you sign. The return on the kept cash is an expectation. A savings account's rate can be cut, and a stock portfolio held for five years can end below where it started. So even when the expected return beats the break-even, financing to invest means taking on a fixed obligation in exchange for an uncertain gain. That is a reason to want a margin. On the default figures, financing wins at an 8% return by $457, a thin reward over five years for carrying $30,400 of debt against investments that could fall. Paying down or avoiding debt is the one return that cannot disappoint, which is why the break-even should be read as a floor rather than a target. The tax on the return matters as much as the return. Long-term capital gains are taxed federally at 0%, 15% or 20% depending on income, while interest from a savings account is taxed at your ordinary rate. At a 22% rate, a 5% savings account earns 3.9% after tax, further below a 6.35% loan than a portfolio taxed at 15%. Where the cash is kept therefore changes the answer as much as how much it earns. Two situations change it further. A promotional rate, such as 0% financing from a manufacturer's lender, puts the break-even return at zero, so almost any return favors financing, though such offers often replace a cash rebate. And a high rate, such as a used-car loan at a lower credit tier, raises the break-even beyond what most safe investments pay.
The cushion that paying cash spends
Money spent on a car stops being available for anything else. A car can be sold, but not quickly, not at a price you control, and not while you still need it to get to work. So the most important number on this page may not be which path finishes ahead, but what each leaves in the bank. In the default example, paying cash leaves $17,000 of a $55,000 balance, about 3.8 months of $4,500 in essential expenses. Financing leaves $47,400, about 10.5 months. Both are more than many households hold. The Federal Reserve's survey of household finances for 2025, published in May 2026, found that 63% of adults would cover a $400 emergency expense using cash or its equivalent, unchanged from the year before. More than a third would not. A household that empties its savings to avoid a car loan and then meets a repair bill, a medical bill or a gap in income will often borrow anyway, on a credit card or a personal loan, at a rate well above what the car loan would have cost. The saving from paying cash can disappear in one such event. That is why the page puts the cushion beside the verdict rather than folding it in. A cushion does not have a return that fits the formula, but it prevents the expensive borrowing that follows a shock. A reasonable approach is to decide how many months of expenses you want to keep, subtract that from savings, and only then ask whether what is left should buy the car outright. If it cannot cover the whole price, the real question is how large a down payment to make, not whether to pay cash.
What the new interest deduction changes, and what it does not
For tax years 2025 through 2028, interest on a car loan can be deductible, which makes financing cheaper after tax for buyers who qualify. The conditions are specific. The vehicle must be new, with its final assembly in the United States, a car, minivan, van, SUV, pickup or motorcycle under 14,000 pounds gross vehicle weight rating, bought for personal use with a loan taken out after December 31, 2024 and secured by a first lien on the vehicle. Up to $10,000 of interest a year counts, reduced by $200 for each $1,000, or part of $1,000, of modified adjusted gross income over $100,000, or $200,000 on a joint return. It is claimed on Schedule 1-A whether or not you itemize. Because eligibility depends on the car and not on the buyer, the page does not ask whether you qualify. It runs both cases side by side. On the default loan, a first payment in October 2026 leaves 27 payments inside the window, and at a 22% marginal rate the deduction saves $771 over them. That lifts the finance path to $38,478 and cuts paying cash's lead from $1,960 to $1,066. The return the cash must beat falls from 7.47% to 6.34% before tax. What the deduction does not do is make borrowing free. It returns your marginal rate on the interest, so at 22% most of every interest dollar is still yours to pay. It ends after 2028, so the later payments of a long loan get no help. It does nothing for a used car, which is what many cash buyers purchase. And it phases out quickly: a full $10,000 claim is gone once MAGI passes $149,000 for a single filer.
Frequently asked questions
Is it better to pay cash for a car or finance it?
It depends on whether your cash can earn more after tax than the loan costs. On the default figures, a 6.35% loan against a 5% return taxed at 15% leaves paying cash $1,960 ahead after five years, and the kept cash would need to earn 7.47% before tax to break even. At 8% financing comes out $457 ahead, but the loan's cost is certain and the return is not.
How does the page keep the comparison fair?
Both paths spend the same money on the same dates. Both put the down payment in on day one. Financing keeps the rest invested and pays the loan from income; paying cash spends it, then invests the loan payment it no longer owes each month. At the end of the loan each path holds a portfolio, and the difference is the answer.
Does the car loan interest deduction change the answer?
It narrows the gap. For tax years 2025 through 2028, up to $10,000 a year of interest on a loan for a new vehicle with final assembly in the United States is deductible whether or not you itemize, reduced $200 for each $1,000 or part of $1,000 of MAGI over $100,000 ($200,000 joint). On the default loan at a 22% rate it saves $771 over the 27 payments inside the window, which cuts paying cash's lead to $1,066 and the break-even return to 6.34%.
How much should I keep in savings after buying a car?
Enough to handle an emergency without borrowing. In the default example, paying cash leaves $17,000, about 3.8 months of essential expenses, while financing leaves $47,400, about 10.5 months. The Federal Reserve's survey for 2025 found that 63% of adults would cover a $400 emergency expense with cash or its equivalent, so more than a third would not.
What return should I assume on the cash?
The one you would actually get. Money left in a savings account earns its savings rate, taxed as ordinary income. Money invested in a stock portfolio can earn more over long periods, but over a five-year loan it can also lose value. The table runs the whole range so you can see where the answer flips.
Why does the page tax the investment return?
Because only the after-tax return is yours to compare with the loan. Long-term capital gains are taxed federally at 0%, 15% or 20%, and savings interest at your ordinary rate. Money in a retirement account is taxed differently, but it is rarely money you would take out to buy a car.
What if I cannot pay the whole price in cash?
Then paying cash is not a real option, and the page says so. The useful question becomes how much to put down: each extra dollar of down payment saves the loan's rate and gives up the return that dollar would have earned.