Free car tools
Free Car Calculators & Tools
Make smarter car decisions with 43 free calculators for auto loans, ownership costs, fuel economy, maintenance, tires, towing and more. No signup, no fees — just answers.
- 43free tools
- 100%free forever
- 0signups needed
Financing & buying
Loans, Leases & Purchase Decisions
Know your payment, your budget and your best deal — before you talk to a dealer.
Auto Loan Calculator
Monthly payment, total interest and amortization — with tax, fees, down payment and extra payments.
- Tax, title & fees included
- Amortization schedule
- Extra payment payoff
Car Affordability Calculator
How much car can you really afford? Based on income, debts and the 20/4/10 rule.
- 20/4/10 rule check
- Budget-based price range
- Monthly payment target
Auto Refinance Calculator
See if refinancing saves you money — new rate, new term, break-even point.
- Monthly savings estimate
- Break-even analysis
- Total interest compare
Down Payment Calculator
How much should you put down? See the effect on payment, interest and loan approval.
- Down payment scenarios
- Interest savings
- Trade-in as down payment
Car Tax & Fees Calculator
True out-the-door price: sales tax, title, registration and dealer fees by state.
- State sales tax rates
- Out-the-door price
- Fee breakdown
Cash vs Finance Calculator
Pay cash or take the loan? Compare total cost including investment opportunity.
- Side-by-side compare
- Opportunity cost
- 0% APR scenarios
Car Lease Calculator
Lease payment with money factor, residual and drive-off — plus lease vs buy verdict.
- Money factor math
- Lease vs buy compare
- Drive-off breakdown
New vs Used Car Calculator
New or used? Compare total cost, depreciation and value for both options.
- Total cost compare
- Depreciation difference
- Sweet-spot age finder
Car Rental Cost Calculator
Estimate rental cost with taxes, fees, insurance and mileage charges included.
- Taxes & fees included
- Insurance options
- Weekly vs daily rates
Car Warranty Cost Calculator
Is an extended warranty worth it? Compare cost vs expected repair bills.
- Break-even analysis
- Coverage compare
- Repair cost data
Lease Mileage Calculator
Project lease miles at turn-in, estimate overage charges, check your pacing, and compare the cheapest way out.
- Live pacing gauge & planner
- Brand charge table
- Upfront vs turn-in vs buyout
Insurance, value & ownership
What It Really Costs to Own
The sticker price is only the start. Insurance, depreciation and running costs decide the real price.
Car Insurance Estimator
Estimate your premium by car, age, location and coverage level before you buy.
- Coverage level compare
- State rate factors
- Discount checklist
Car Depreciation Calculator
How fast your car loses value year by year — by age and mileage.
- Year-by-year value curve
- Mileage adjustments
- Best resale timing
Resale & Trade-In Value
Trade-in vs private-party value by make, model, year, mileage and condition.
- Trade-in vs private sale
- Condition adjustments
- Mileage impact
Car Ownership Cost Calculator
True 5-year cost: payments, fuel, insurance, maintenance and depreciation in one view.
- 5-year total cost
- Cost per mile
- Compare two cars
Car Maintenance Cost Calculator
Annual maintenance budget by make, model, age and mileage — what to expect.
- Annual cost estimate
- By make & model
- Age-based curve
Maintenance Schedule Calculator
Personal service schedule: oil, filters, brakes, fluids — by your mileage and driving.
- Custom service timeline
- Severe vs normal duty
- Cost forecast
Car Repair Cost Estimator
Fair price for common repairs: brakes, alternator, transmission, engine and more.
- Parts + labor split
- Shop vs dealer prices
- Common repairs database
Car Insurance Deductible Calculator
Compare $250 vs $500 vs $1,000 deductibles side by side over 10 years — with break-even chart and claim surcharge math.
- 3-way cost comparison
- Break-even chart
- Claim surcharge modeling
Diminished Value Calculator
Estimate your car’s value loss after an accident with 17c, classic and repair-based methods — plus a demand letter.
- 3 methods side by side
- 50-state law table
- Demand letter template
Fuel, trips & driving
MPG, Fuel Spend & Trip Budgets
Know your real fuel economy and what every mile — and every trip — costs.
MPG Calculator
True miles per gallon from your fill-ups — city, highway or combined, with tracking log.
- True MPG from fill-ups
- Cost per mile
- MPG tracking log
Fuel Cost Calculator
Daily, monthly, annual and per-mile fuel spend for your car and local gas price.
- Monthly & annual cost
- Cost per mile
- Gas price scenarios
Road Trip Cost Calculator
Plan the drive: fuel, tolls, stops and total trip budget for any route.
- Fuel + tolls estimate
- Refuel stop planner
- Per-person cost split
Commute Cost Calculator
What your daily commute really costs — fuel, tolls, wear and your time.
- Daily & annual cost
- Time value included
- Carpool savings
Toll Cost Calculator
Estimate toll charges for your route — with and without a transponder.
- Route toll estimate
- Transponder savings
- Cash vs tag rates
Driving Cost Calculator
Daily and annual driving cost — fuel, depreciation share and maintenance per mile.
- True cost per mile
- Annual total
- IRS rate compare
Maintenance & repair
Service, Fluids, Brakes & Battery
Stay ahead of service — costs, intervals and capacities for your specific car.
Oil Change Calculator
Cost and interval for your car — conventional vs synthetic, DIY vs shop.
- Cost estimate
- Interval by oil type
- DIY savings
Oil Capacity Lookup
Engine oil capacity and spec for your make and model — no more guessing.
- Quarts / liters needed
- Oil spec & viscosity
- Filter info
Brake Pad Life Calculator
How many miles your brake pads have left — based on driving style and pad type.
- Remaining life estimate
- Pad material compare
- Replacement timing
Car Battery Calculator
12V battery: replacement cost, expected life, health check and voltage guide.
- Replacement cost
- Life expectancy
- Voltage health check
Tires, wheels & towing
Sizes, Fitment & Safe Towing
Size up tires correctly, dial in fitment, and know exactly what you can tow.
Tire Size Calculator
Compare sizes: diameter, sidewall, speedometer error, RPM and clearance.
- Plus/minus sizing
- Speedometer error
- Visual size compare
Tire Pressure Calculator
Right PSI for your load and conditions — plus temperature adjustments.
- Load-based PSI
- Temp adjustments
- MPG & wear impact
Tire Life Calculator
How long your tires will last — by treadwear rating, driving and rotation habits.
- Mileage estimate
- Rotation impact
- Replacement timing
Tire Load & Speed Guide
Decode load index and speed ratings — what your tire markings really mean.
- Load index chart
- Speed rating chart
- Marking decoder
Tire Stretch Calculator
Stretched fitment math: tire width vs wheel width, sidewall angle and safety notes.
- Stretch ratio
- Safe combinations
- Visual guide
Wheel Fitment Calculator
Offset, backspacing and bolt pattern — will those wheels actually fit?
- Offset converter
- Backspacing math
- Clearance check
Towing Capacity Calculator
Can you tow it? Trailer, tongue weight and payload vs your real limits.
- GCWR & payload check
- Tongue weight math
- 5th wheel & gooseneck
Engine & mechanical
Gearing, Power & Fluids
For the gearheads: ratios, displacement, conversions and fluid capacities.
Gear Ratio Calculator
RPM, speed and effective ratio — including tire size changes.
- RPM at speed
- Tire size effect
- Ratio compare
Horsepower Converter
HP to kW, PS, and torque conversions — plus power-to-weight.
- HP / kW / PS
- Torque conversions
- Power-to-weight
Engine Displacement Calculator
Bore × stroke × cylinders = displacement in cc, liters and cubic inches.
- cc / liters / ci
- Bore & stroke math
- Overbore effect
Compression Ratio Calculator
Static compression ratio from cylinder, chamber, gasket and piston volumes.
- Static ratio
- Volume inputs
- Fuel requirement hint
Fluid Capacity Lookup
Transmission, coolant and brake fluid capacities and specs for your car.
- Trans / coolant / brake
- Fluid specs
- Change intervals
Alternator Size Calculator
How many amps your electrical load needs — audio, lights, accessories and more.
- Load calculator
- Upgrade sizing
- Audio system math
Free Car Calculators for Every Driver
Buying, financing, insuring, and maintaining a car involves dozens of small math problems that add up to thousands of dollars. These 43 free car calculators answer them in seconds — from your monthly auto loan payment with tax and fees, to your car’s true five-year ownership cost, to whether your truck can safely tow that trailer.
Every tool on this page is free to use with no signup. They run entirely in your browser, so your numbers stay private.
What You Can Calculate Here
- Financing & buying: auto loan payments with tax and fees, affordability, refinancing, down payments, cash vs finance, leases, new vs used, rentals and warranties.
- Insurance, value & ownership: insurance estimates, depreciation curves, resale and trade-in values, five-year ownership cost, maintenance budgets and repair estimates.
- Fuel, trips & driving: real-world MPG, monthly and annual fuel spend, road-trip budgets, commute costs, tolls and true cost per mile.
- Maintenance & repair: service schedules, oil change costs and intervals, oil capacities, brake pad life and 12V battery health.
- Tires, wheels & towing: tire size comparisons, correct pressure, tire life, load and speed ratings, wheel fitment and safe towing limits.
- Engine & mechanical: gear ratios, horsepower conversions, displacement, compression ratio, fluid capacities and alternator sizing.
Frequently Asked Questions
Are these car calculators really free?
Yes. Every calculator on this page is completely free with no signup, no account, and no usage limits.
Do I need to create an account to use them?
No. All calculations happen in your browser. We don’t collect your inputs or require any personal information.
How accurate are the estimates?
They use standard industry formulas and current market assumptions. Results are estimates for planning — your dealer, lender, or insurer will confirm final numbers.
Will more tools be added?
Yes. Tools marked “Coming soon” are in development and will go live here as they’re finished.
Do you have EV-specific calculators too?
Yes — our EV Tools hub has 13 free calculators for charging costs, range, battery health, and EV ownership.