Automotive Calculators
Automotive Calculators
Our free automotive calculators help you make smarter decisions about buying, leasing, owning, and driving a vehicle — from monthly loan payments and depreciation curves to gas costs, EV savings, and true total cost of ownership.
Before You Buy
- Car Loan Calculator — Calculate your monthly payment, total interest, and total cost for any auto loan
- Car Payment Affordability Calculator — Find out how much car you can afford using the 20/4/10 rule
- Car Depreciation Calculator — See how much a vehicle loses in value year by year
- Car Lease vs. Buy Calculator — Compare the true long-term cost of leasing versus financing
Owning and Running a Vehicle
- Vehicle Total Cost of Ownership Calculator — Add up all the real costs: loan, insurance, gas, maintenance, and depreciation
- Gas Cost Calculator — Estimate fuel costs for a trip or an entire year
- Fuel Economy Calculator — Calculate your actual MPG and cost per mile from fill-up data
Comparing Options
- EV Savings Calculator — Compare electric vs. gas running costs and find your break-even point
- Tire Size Calculator — Decode tire size codes, compare two sizes, and check speedometer accuracy
Key Automotive Terms
- APR (Annual Percentage Rate)
- The true yearly cost of a car loan, including interest and fees. Always compare APR rather than monthly payment when shopping loans.
- Depreciation
- The loss in a vehicle's value over time. New cars typically lose 20–30% of their value in the first year, and 15–20% per year thereafter.
- Residual Value
- The estimated value of a leased vehicle at the end of the lease term. A higher residual value means lower monthly lease payments.
- Money Factor
- The lease equivalent of an interest rate. Multiply by 2,400 to convert to an approximate APR.
- Total Cost of Ownership (TCO)
- The complete cost to own and operate a vehicle over a given period, including purchase price, financing, insurance, fuel, maintenance, and depreciation.
- MPG / L/100km
- Miles per gallon (US) and liters per 100 kilometers (metric) are the standard fuel economy measures. Lower L/100km and higher MPG both mean better efficiency.
- Equity
- When buying, equity is the portion of the car's value you own outright. When leasing, you build no equity.
Frequently Asked Questions
- What is the 20/4/10 car buying rule?
- Put at least 20% down, finance for no more than 4 years, and keep total vehicle expenses (payment + insurance) under 10% of gross monthly income. Following this rule keeps car costs manageable and avoids being underwater on the loan.
- How quickly do cars depreciate?
- Most new cars lose about 20–30% of their value in the first year and roughly 15–20% per year for the next four years. After five years, a typical vehicle retains about 40–50% of its original purchase price — though this varies significantly by make, model, and market conditions.
- Is leasing or buying a car better?
- It depends on your priorities. Leasing typically offers lower monthly payments and a new car every few years, but you build no equity and face mileage limits. Buying costs more upfront but eventually eliminates the monthly payment and builds an asset you can sell or trade. Long-term, buying is almost always less expensive.
- How much does it actually cost to own a car?
- The American Automobile Association (AAA) estimates average total ownership costs at $10,000–$12,000 per year for a new car when you include depreciation, financing, insurance, fuel, maintenance, and registration. SUVs and trucks cost more; small sedans less.
- How do I get the best car loan rate?
- Check your credit score before shopping. Get pre-approved from your bank or credit union before visiting a dealership — this gives you negotiating leverage. Credit union rates are often 1–2% lower than dealer financing. Even a 1% rate reduction saves hundreds to thousands in interest over the life of the loan.