Our calculators
Car Affordability Calculator
Enter your income, debts, down payment, and rate — see the maximum car price that fits the 20/4/10 rule and your debt-to-income limits.
Open calculator →Auto Loan Payment Calculator
Monthly payment with tax, fees, and trade-in included, plus total interest and a yearly payoff schedule.
Open calculator →Lease vs. Buy Calculator
Compare the total cost of leasing and buying the same car over the same period — and see which one actually wins.
Open calculator →Trade-In Equity Calculator
Find out if you have positive equity or are upside down on your current loan, and what your next loan payment would look like.
Open calculator →Auto Refinance Break-Even Calculator
A lower rate sounds great, but fees eat into the savings. See how many months until refinancing actually pays off.
Open calculator →Total Cost of Ownership Calculator
The payment is only part of it. Add insurance, gas, maintenance, and depreciation to see what a car really costs per month and per mile.
Open calculator →Down Payment Savings Planner
How long until you hit your down payment goal? Enter what you have saved and what you can set aside each month.
Open calculator →Why CarCanAfford?
The full monthly cost, not just the payment
Most calculators show the loan payment and stop there. Ours add insurance, gas or charging, and maintenance — the costs that turn an “affordable” payment into a stretch.
Private by design
Every calculation runs entirely in your browser. No accounts, no email capture, no “get your rate” forms — your income and debts never leave your device.
Free, no signup
All tools are free with no usage limits. We keep the lights on with advertising, which is why you will never hit a paywall before seeing a result.
Plain-language guides
Each calculator ships with a short guide explaining the math — the 20/4/10 rule, DTI ratios, depreciation, break-even — written for first-time buyers, not bankers.
How to work out what you can afford
The most widely used rule for car buying is the 20/4/10 rule: put at least 20% down, take a loan of 4 years (48 months) or less, and keep your total monthly car costs — loan payment, insurance, and gas or charging — at or below 10% of your gross monthly income. Each part of the rule protects you in a different way: the down payment keeps you from owing more than the car is worth, the short loan keeps interest costs down, and the 10% cap keeps the car from crowding out everything else in your budget.
Example: with $75,000 of annual income ($6,250 a month), the 10% cap gives you about $625 a month for everything car-related. If insurance runs about $150 and gas about $180, that leaves roughly $295 for the loan payment itself — which, at a typical rate over 48 months, supports a loan of roughly $12,000 to $13,000. Add a 20% down payment and you are looking at a car in the roughly $15,000 to $16,000 range. Our affordability calculator does exactly this math — and also checks your debt-to-income ratios, so you can see which limit is binding.
Three things surprise first-time buyers most: (1) insurance and gas can add 50% or more on top of the loan payment; (2) stretching a loan to 72 or 84 months lowers the payment but adds thousands in interest and keeps you owing money on a car that has lost much of its value; (3) a new car typically loses roughly 15–20% of its value in the first year, so a small down payment can leave you upside down almost immediately. Budget for all three before you shop.
Frequently asked questions
Are these calculators really free?
Yes. Every tool is free with no usage limits and no account required.
Is my financial data sent anywhere?
No. All calculations happen locally in your browser using JavaScript. There are no user accounts, and the numbers you enter are never transmitted to us.
Are the results financial advice?
No. The calculators produce good-faith estimates based on standard auto loan math and widely used guidelines like the 20/4/10 rule. Loan programs, rates, taxes, and fees vary — for decisions involving real money, talk to a qualified financial professional.
What is the 20/4/10 rule?
It is the guideline most car-buying experts recommend: put at least 20% down, keep the loan term to 4 years (48 months) or less, and keep total monthly car costs — payment, insurance, and gas — at or below 10% of your gross monthly income.
Do I need to create an account?
No. Everything works in your browser on phone, tablet, or desktop — no signup, no downloads.
I am a first-time buyer. Where should I start?
Start with the Car Affordability Calculator to find your price range, then use the Down Payment Savings Planner to map how long saving will take, and the Total Cost of Ownership Calculator so insurance, gas, and depreciation do not surprise you after you buy.