{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"car-loan"},"result":{"entity_type":"calculator","id":"car-loan","calculator_id":"car-loan","canonical_url":"https://tttkmbb.com/finance/car-loan","name":"Car Loan Calculator","title":"Car Loan Calculator – Amount Financed, Monthly Payment and Total Cost with Tax, Fees and Trade-In","category":"finance","category_name":"Finance","tool_name":"calculate_car_loan","featured_mcp_tool":false,"description":"Computes the amount financed for a vehicle purchase from price, sales tax, fees, down payment and trade-in, then the level monthly payment, total interest and total cost of the car over the loan.","use_when":"You are buying a car with an installment loan and want the monthly payment or the full cost including sales tax, dealer fees and a trade-in credit.","do_not_use_when":"You are leasing rather than buying (use car-lease), or you only have a loan amount and rate (use loan-payment).","inputs":[{"name":"vehicle_price","label":"Vehicle price","type":"number","required":true,"max":100000000,"exclusive_min":0,"description":"Negotiated purchase price before tax and fees.","example":30000},{"name":"down_payment","label":"Down payment","type":"number","required":false,"default":0,"min":0,"max":100000000,"description":"Cash paid at signing.","example":5000},{"name":"trade_in_value","label":"Trade-in value","type":"number","required":false,"default":0,"min":0,"max":100000000,"description":"Credit for the vehicle traded in (net of any loan still owed on it).","example":0},{"name":"sales_tax_percent","label":"Sales tax","type":"number","unit":"%","required":false,"default":0,"min":0,"max":30,"description":"Sales tax rate applied to the taxable price.","example":6},{"name":"annual_rate_percent","label":"Annual interest rate (APR)","type":"number","unit":"%","required":true,"min":0,"max":100,"description":"Loan APR in percent; the monthly rate is this / 12.","example":7},{"name":"term_months","label":"Term","type":"integer","unit":"months","required":false,"default":60,"min":1,"max":120,"description":"Loan term in months (36, 48, 60, 72 and 84 are common).","example":60},{"name":"fees","label":"Fees financed","type":"number","required":false,"default":0,"min":0,"max":1000000,"description":"Documentation, title and registration fees rolled into the loan.","example":0},{"name":"trade_in_reduces_tax","label":"Trade-in reduces taxable price","type":"boolean","required":false,"default":true,"description":"Most US states tax vehicle_price − trade_in_value; set false where tax is charged on the full price (e.g. California, Virginia).","example":true}],"outputs":[{"name":"sales_tax","label":"Sales tax","type":"number","decimals":2,"description":"Taxable price × sales_tax_percent / 100."},{"name":"amount_financed","label":"Amount financed","type":"number","decimals":2,"description":"vehicle_price + sales_tax + fees − down_payment − trade_in_value."},{"name":"monthly_payment","label":"Monthly payment","type":"number","decimals":2,"description":"Level payment from the amortization formula."},{"name":"total_interest","label":"Total interest","type":"number","decimals":2,"description":"monthly_payment × term_months − amount_financed."},{"name":"total_of_payments","label":"Total of payments","type":"number","decimals":2,"description":"monthly_payment × term_months."},{"name":"total_cost","label":"Total cost of the car","type":"number","decimals":2,"description":"vehicle_price + sales_tax + fees + total_interest (down payment and trade-in are part of this, not additional)."}],"input_schema":{"type":"object","properties":{"vehicle_price":{"description":"Negotiated purchase price before tax and fees.","type":"number","maximum":100000000,"exclusiveMinimum":0,"examples":[30000]},"down_payment":{"description":"Cash paid at signing.","type":"number","minimum":0,"maximum":100000000,"default":0,"examples":[5000]},"trade_in_value":{"description":"Credit for the vehicle traded in (net of any loan still owed on it).","type":"number","minimum":0,"maximum":100000000,"default":0,"examples":[0]},"sales_tax_percent":{"description":"Sales tax rate applied to the taxable price. Unit: %.","type":"number","minimum":0,"maximum":30,"default":0,"examples":[6],"x-unit":"%"},"annual_rate_percent":{"description":"Loan APR in percent; the monthly rate is this / 12. Unit: %.","type":"number","minimum":0,"maximum":100,"examples":[7],"x-unit":"%"},"term_months":{"description":"Loan term in months (36, 48, 60, 72 and 84 are common). Unit: months.","type":"integer","minimum":1,"maximum":120,"default":60,"examples":[60],"x-unit":"months"},"fees":{"description":"Documentation, title and registration fees rolled into the loan.","type":"number","minimum":0,"maximum":1000000,"default":0,"examples":[0]},"trade_in_reduces_tax":{"description":"Most US states tax vehicle_price − trade_in_value; set false where tax is charged on the full price (e.g. California, Virginia).","type":"boolean","default":true,"examples":[true]}},"additionalProperties":false,"required":["vehicle_price","annual_rate_percent"]},"output_schema":{"type":"object","properties":{"sales_tax":{"description":"Taxable price × sales_tax_percent / 100.","type":"number"},"amount_financed":{"description":"vehicle_price + sales_tax + fees − down_payment − trade_in_value.","type":"number"},"monthly_payment":{"description":"Level payment from the amortization formula.","type":"number"},"total_interest":{"description":"monthly_payment × term_months − amount_financed.","type":"number"},"total_of_payments":{"description":"monthly_payment × term_months.","type":"number"},"total_cost":{"description":"vehicle_price + sales_tax + fees + total_interest (down payment and trade-in are part of this, not additional).","type":"number"}}},"formula":"taxable = vehicle_price − trade_in_value (or vehicle_price if trade_in_reduces_tax = false); sales_tax = taxable × sales_tax_percent/100; amount_financed = vehicle_price + sales_tax + fees − down_payment − trade_in_value; i = annual_rate_percent/1200; monthly_payment = amount_financed × i / (1 − (1 + i)^−term_months); total_cost = vehicle_price + sales_tax + fees + total_interest","sources":[{"name":"CFPB – Auto loans: shopping for a loan and comparing costs","url":"https://www.consumerfinance.gov/consumer-tools/auto-loans/","type":"government","retrieved_at":"2026-09-24"},{"name":"FTC – Financing or Leasing a Car","url":"https://consumer.ftc.gov/articles/financing-or-leasing-car","type":"government","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Amortization calculator (annuity payment formula)","url":"https://en.wikipedia.org/wiki/Amortization_calculator","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"30,000 car, 5,000 down, 6 % tax, 7 % APR, 60 months","inputs":{"vehicle_price":30000,"down_payment":5000,"sales_tax_percent":6,"annual_rate_percent":7,"term_months":60},"expected":{"sales_tax":1800,"amount_financed":26800,"monthly_payment":530.67,"total_interest":5040.33,"total_of_payments":31840.33,"total_cost":36840.33},"url":"https://tttkmbb.com/api/v1/calculate/car-loan?vehicle_price=30000&down_payment=5000&sales_tax_percent=6&annual_rate_percent=7&term_months=60"},{"name":"45,000 car, 10,000 trade-in, 3,000 down, 8.25 % tax, 500 fees, 4.9 % for 72 months","inputs":{"vehicle_price":45000,"down_payment":3000,"trade_in_value":10000,"sales_tax_percent":8.25,"annual_rate_percent":4.9,"term_months":72,"fees":500},"expected":{"sales_tax":2887.5,"amount_financed":35387.5,"monthly_payment":568.27,"total_interest":5528.18,"total_cost":53915.68},"url":"https://tttkmbb.com/api/v1/calculate/car-loan?vehicle_price=45000&down_payment=3000&trade_in_value=10000&sales_tax_percent=8.25&annual_rate_percent=4.9&term_months=72&fees=500"}],"faq":[{"q":"Is sales tax charged before or after the trade-in?","a":"In most US states the trade-in value is deducted before tax is calculated; a few states (California, Virginia, Michigan above a cap, and others) tax the full price. Set trade_in_reduces_tax accordingly."},{"q":"Does a longer term save money?","a":"It lowers the monthly payment but raises total interest: 26,800 at 7 % costs 5,040 interest over 60 months but about 6,100 over 72 months."}],"tags":["car loan","auto loan","car payment","vehicle financing","trade-in","sales tax on car"],"related":[{"calculator_id":"loan-payment","reason":"Plain amortization for any loan amount."},{"calculator_id":"car-lease","reason":"Compare with leasing the same vehicle."},{"calculator_id":"sales-tax","reason":"Sales tax on its own."}],"links":{"html":"https://tttkmbb.com/finance/car-loan","markdown":"https://tttkmbb.com/finance/car-loan.md","json":"https://tttkmbb.com/finance/car-loan.json","api":"https://tttkmbb.com/api/v1/calculate/car-loan","schema":"https://tttkmbb.com/api/v1/calculators/car-loan","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:47:10Z","next_actions":[{"tool":"run_calculator","calculator_id":"car-loan","reason":"Run Car Loan Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/finance/car-loan.md"}}