Car Affordability Calculator
Don't start from a sticker price — start from your paycheck. Enter your take-home pay and this calculator works backwards through the loan math to the maximum car price you can truly afford, including insurance, fuel, and maintenance.
Educational estimate — not professional financial advice. Results depend on the numbers you enter; real offers depend on credit, taxes, and fees. Read the FAQ before deciding.
Looking for payments on a car you already picked? That's the opposite direction — try the loan calculator or the auto loan amortization schedule instead.
Your numbers
15% is the common guideline; the 20/4/10 rule uses 10%.
How the math works
Most calculators go price → payment. This one goes income → price, reversing the annuity formula:
budget = income × pct / 100
extras = insurance + fuel + maintenance (per month)
maxPayment = budget − extras
maxLoan = maxPayment × (1 − (1+r)^−n) / r where r = APR/12, n = months
maxPrice = maxLoan / (1 − downPayment%)
The down payment covers part of the price, so the loan only needs to cover the rest — dividing by (1 − down %) scales the affordable loan up to the affordable sticker price.
The 20/4/10 rule, explained
20% down keeps you from owing more than the car is worth the day you drive off. 4 years max on the term limits total interest and the risk of an upside-down loan. 10% of gross income for all car costs leaves room for housing, savings, and life. The check above tests your numbers against all three.
Related: already picked a car? Run the loan calculator or loan amortization schedule for its exact payments.
Frequently asked questions
How much car can I afford on my salary?
A widely used guideline is to spend no more than 15% of your monthly take-home pay on all car costs combined — payment, insurance, fuel, and maintenance. Enter your income in the calculator above and it works backwards through the loan math to the maximum sticker price that fits that budget.
What is the 20/4/10 rule for buying a car?
The 20/4/10 rule says: put at least 20% down, finance for no more than 4 years (48 months), and keep total car expenses at or below 10% of your gross income. The calculator checks your numbers against all three rules and flags any violations.
Should insurance and gas count toward my car budget?
Yes. The true cost of a car is the payment plus insurance, fuel, and maintenance. This calculator subtracts those ownership costs from your budget first, then computes the loan — and the car price — from what is left. Ignoring them is the most common way buyers overextend themselves.
How does this calculator compute the maximum car price?
It reverses the standard loan payment formula. From your affordable monthly payment P, APR r and term n, the maximum loan is P × (1 − (1+r)^−n) / r. Dividing that loan by (1 − down-payment %) gives the maximum price, because the down payment covers part of the price.
Does a bigger down payment let me afford a more expensive car?
Yes, two ways: it reduces the amount you must borrow, and it directly raises the affordable price for the same monthly payment — a 20% down payment means the loan only needs to cover 80% of the price, so the affordable price is the loan divided by 0.8.
Is a 72 or 84 month car loan a bad idea?
Longer terms lower the monthly payment but raise total interest and the risk of owing more than the car is worth. The 20/4/10 rule caps financing at 48 months for this reason. The calculator shows total interest for any term so you can compare the true cost.
How does APR change how much car I can afford?
A higher APR means more of each payment goes to interest, so the same monthly payment supports a smaller loan — and a cheaper car. For example, at the same payment and term, a 9% APR buys noticeably less car than a 5% APR. Try different APRs in the calculator to see the effect.
New vs used — which can I afford more of?
The math is identical; what changes are the inputs. Used cars usually cost less but may carry higher APRs and higher maintenance estimates, while new cars often have lower APRs and warranties. Enter realistic ownership costs for each scenario and compare the resulting maximum prices.
What counts as take-home pay for this calculator?
Take-home pay is what lands in your account after taxes and deductions — not your gross salary. Using gross pay inflates the budget and the affordable price. If you only know your gross pay, a rough estimate is 70–80% of gross, but your actual pay stub is more accurate.
What is total cost of ownership and why does it matter?
Total cost of ownership is everything you will spend: down payment, all loan payments (principal plus interest), insurance, fuel, and maintenance over the years you own the car. Two cars with the same sticker price can have very different ownership costs, so the calculator shows a 5-year total to make comparisons honest.
How is this different from an auto loan calculator?
An auto loan calculator starts from a known car price and tells you the monthly payment. This tool works in the opposite direction: it starts from your income and tells you the maximum car price you can afford. If you already picked a car, use an auto loan calculator instead.
Is this calculator financial advice?
No. This is an educational estimate based on the numbers you enter — not professional financial advice. Real loan offers depend on credit history, lender terms, taxes, and fees not modeled here. Talk to a qualified financial professional before making a purchase decision.
Free tool by NRTechStudio