Free tools · No signup
Free Car Calculators & Tools
Decode a code, check a VIN, price a loan or plan a service. Every tool is free, and none of them asks you to sign up.
Tool status
21 / 21
ready to use
today
These four have a quick version on this page. Every tool has a full page of its own.
- tools in the set
- 21
- ready to use, each with its own page
- 21
- groups, from diagnostics to detailing
- 4
- accounts or sign-ups needed
- 0
01Workbench
Try four of them right here.
No account and nothing to install. What you type stays in your browser.
Free, with no account. You get the meaning, the usual causes and whether it is safe to keep driving.
What it tells you
- What the code means, in plain English
- The usual causes, most likely first
- Whether it is safe to keep driving
This is the quick version. The full tool has more options, the formula behind it and a worked example.
Open the full tool02Diagnostics tools
Find out what the car is telling you.
Start from the code or the symptom, then see what the repair should cost before you call a shop.
- Ready
OBD2 Code Lookup
Enter any OBD2 code for its meaning, severity, likely causes and first steps.
- Ready
Repair Cost Estimator
Build a repair estimate from parts, labor hours and shop rate, and compare it with national averages.
- Ready
Check Engine Light Checker
Steady or flashing? Find out whether it is safe to keep driving and what to do next.
- Ready
Car Symptom Diagnosis Tool
Pick what the car is doing and see the common causes and what to check first.
These tools belong to theOBD2 library
03Buying & Finance tools
Run the numbers before you sign.
Check the car, then the loan, then the price you will really pay once tax and fees are added.
- Ready
VIN Decoder
Decode a 17-character VIN into year, make, model, engine and plant.
- Ready
Car Payment Calculator
Work out the monthly payment, total interest and payoff schedule for a car loan.
- Ready
Car Affordability Calculator
Find the car price your income supports using the 20/4/10 rule.
- Ready
Car Sales Tax Calculator
Work out the sales tax on a car from your state and local rates and your trade-in.
- Ready
Out-the-Door Price Calculator
Add tax, registration and dealer fees to see the real price you will pay.
- Ready
Car Depreciation Calculator
See what a car is likely to be worth each year you own it.
- Ready
Car Lease Calculator
Calculate a monthly lease payment and convert the money factor to an APR.
- Ready
Lemon Law Checker
Check a problem car against the repair and timing tests state lemon laws use.
These tools belong to theUsed Cars library
04Maintenance & Fuel tools
Know what is due and what it costs.
Know which service is due, what the car costs to run and how far a tank really takes you.
- Ready
Oil Change Interval Calculator
Get your next oil change date and mileage from your oil type and driving habits.
- Ready
Maintenance Schedule Generator
List the services due now and next for your mileage, with typical intervals.
- Ready
Car Ownership Cost Calculator
Add up fuel, insurance, maintenance and depreciation over five years.
- Ready
MPG Calculator
Turn miles driven and gallons used into MPG, L/100km and cost per mile.
- Ready
Fuel Cost Calculator
Estimate the fuel cost and gallons needed for any trip.
These tools belong to theMaintenance library
05Tires & Detailing tools
Get the fit, the pressure and the finish right.
Compare tire sizes, correct the pressure for the weather and price a detail before you book one.
- Ready
Tire Size Calculator
Compare two tire sizes for diameter, sidewall and speedometer error.
- Ready
Tire Pressure Calculator
Adjust tire pressure for a temperature change and convert PSI, bar and kPa.
- Ready
Window Tint Law Checker
Work out the net tint on a window and check it against your state's limit.
- Ready
Detailing Cost Estimator
Estimate a detailing price range and compare doing it yourself with paying a pro.
These tools belong to theDetailing library
06Start here
Five good places to start.
If you are not sure which tool you need, find the moment you are in.
- 01
A warning light has just come on and you have the code.
OBD2 Code Lookup
- 02
You are about to go and look at a used car.
VIN Decoder
- 03
A dealer wants to talk about the monthly payment.
Car Payment Calculator
- 04
You are not sure which service the car is due.
Maintenance Schedule Generator
- 05
A shop has handed you a quote for a repair.
Repair Cost Estimator
07How they work
Built to be checked, not just trusted.
A tool is only useful if you can see what it assumed. These four rules apply to every one we build.
Free, with no account
No sign-up, no email address and no paywall standing between you and a result.
Private by design
The tools on this page do their work in your browser. What you type is not sent to us.
Assumptions on show
Each tool says what it assumes, so you can tell an estimate from a quote.
Read the disclaimerTied to the guides
Every tool belongs to a library that explains the result and what to do next.
08Questions
Tool questions, answered.
Short answers about cost, accuracy and privacy.
Are the CarTipsMentor tools really free?
Yes. Every tool is free to use, and none of them asks for an account, an email address or a payment.
Where do the figures in the tools come from?
The formulas are standard, and each tool page shows its own. Default figures such as average loan rates, repair costs and running costs come from named sources, including Experian, AAA and CarMD, which are listed at the foot of each tool page.
How accurate are the results?
The calculators use standard formulas, and a result is only as exact as the figures you enter. Lender fees, taxes, local labor rates and your own vehicle all change the real number, so treat a result as a starting point and confirm it with a written quote.
Do you keep what I type into a tool?
No. The tools on this page run in your browser, so the codes, VINs and figures you enter are not sent to CarTipsMentor or stored by us.