Car Affordability Calculator
Find out how much car you can afford. Use the 20/4/10 rule (20% down, 4-year loan, car costs at most 10% of gross income) or start from the monthly payment you're comfortable with. Sales tax, trade-in and your loan rate are included.
Before taxes. Optional for the budget method.
Counted in the 10% limit (insurance; some people add fuel and maintenance).
Added to the price and financed.
How to use the Car Affordability Calculator
- Pick a method: the 20/4/10 rule or your own monthly budget.
- Enter your gross yearly income and monthly insurance or other car costs.
- Set the down payment (percent for the rule, cash for the budget method) and any trade-in.
- Enter the loan APR, term and sales tax.
- Read the maximum car price and compare loan terms in the table.
The 20/4/10 rule
A popular guideline for buying a car without overextending yourself:
- 20: put at least 20% down, so you don't owe more than the car is worth as it depreciates.
- 4: finance for no more than 4 years (48 months).
- 10: keep total monthly car costs (the payment plus insurance; some versions include fuel and maintenance) at or below 10% of gross monthly income.
How the maximum price is calculated
First the affordable payment: P = gross yearly income ÷ 12 × 10% − other car costs. The loan that payment supports comes from the present value of a loan:
Loan = P × (1 − (1 + r)−n) ÷ r
with r = APR ÷ 12 and n = months. Because the down payment is a percentage of the price and sales tax is financed, the price is (loan + trade-in) ÷ (1 + tax rate − down %). With a fixed cash down payment it is (loan + down + trade-in) ÷ (1 + tax rate).
Example: $75,000 a year is $6,250 a month; 10% is $625, minus $150 insurance = $475 a month. At 7% for 48 months that supports a loan of about $19,836, so with 20% down and 7% sales tax the maximum price is about $22,800.
Car price by income (20/4/10 rule)
48-month loan at 7% APR, 20% down, 7% sales tax.
| Gross income | 10% per month | Max price (payment only) | Max price ($150/mo insurance in the 10%) |
|---|---|---|---|
| $40,000 | $333 | $16,000 | $8,800 |
| $50,000 | $417 | $20,000 | $12,800 |
| $60,000 | $500 | $24,000 | $16,800 |
| $75,000 | $625 | $30,000 | $22,800 |
| $100,000 | $833 | $40,000 | $32,800 |
| $125,000 | $1,042 | $50,000 | $42,800 |
| $150,000 | $1,250 | $60,000 | $52,800 |
| $200,000 | $1,667 | $80,000 | $72,800 |
Longer loans (60–84 months) lower the payment and make a pricier car look affordable, but you pay more interest and may owe more than the car is worth for years. The term table in the results shows the trade-off.
Frequently asked questions
How much car can I afford on my salary?
With the 20/4/10 rule, keep car costs at 10% of gross monthly income. On $75,000 a year that is $625 a month; after $150 of insurance, a $475 payment over 48 months at 7% with 20% down and 7% sales tax supports a car of about $22,800.
What is the 20/4/10 rule for buying a car?
Put at least 20% down, finance for no more than 4 years, and keep total monthly car costs (payment plus insurance, and in some versions fuel and maintenance) at or below 10% of your gross monthly income.
Should I include insurance in the 10%?
Many versions of the rule count insurance, and stricter ones include fuel and maintenance too. Enter whatever you want counted in 'Insurance & other car costs'; the payment limit is reduced by that amount.
Is a 72- or 84-month car loan a good idea?
It lowers the payment but increases total interest, and the car loses value faster than you pay it down, so you may owe more than it is worth. The table shows how much more car a longer term buys and what it costs in interest.
How is sales tax handled?
Sales tax is added to the price and assumed to be financed. The calculator solves for the price where price + tax − down payment − trade-in equals the loan your payment can support.
What if I already have a monthly budget?
Switch to 'My monthly budget', enter the payment and cash down. If you also enter your income, the calculator shows whether your payment plus other car costs stays within 10% of gross income.
Does this check my credit or contact lenders?
No. It is a planning tool that runs in your browser. Your actual rate depends on your credit, the lender and whether the car is new or used.