Calculators

Auto loan calculator API

Computes an auto loan payment after down payment, trade-in, and sales tax, then amortizes via M = P*r/(1-(1+r)^-n). Answers 'What is my car payment?','How much will I finance after my down payment and trade-in?'.

Price$0.01per request

MethodPOST

Route/v1/calc/loan-auto

StatusLive

MIME typeapplication/json

Rate limit120/minute

CacheNo cache

loanautocaramortizationtrade-insales-taxcalculator

API URLhttps://x402.hexl.dev/v1/calc/loan-auto

Integration docs

Example request

{
  "vehiclePrice": 30000,
  "downPayment": 5000,
  "salesTaxPct": 6,
  "annualRatePct": 5,
  "termMonths": 60
}

Example response

{
  "amountFinanced": 26800,
  "monthlyPayment": 505.75,
  "salesTax": 1800,
  "totalPaid": 30344.94,
  "totalInterest": 3544.94,
  "totalCostOfOwnership": 37144.94,
  "breakdown": {
    "vehiclePrice": 30000,
    "downPayment": 5000,
    "tradeInValue": 0,
    "salesTax": 1800,
    "annualRatePct": 5,
    "termMonths": 60
  }
}

Input schema

{
  "type": "object",
  "required": [
    "vehiclePrice",
    "annualRatePct",
    "termMonths"
  ],
  "properties": {
    "vehiclePrice": {
      "type": "number",
      "description": "Sticker/negotiated vehicle price.",
      "examples": [
        30000
      ]
    },
    "downPayment": {
      "type": "number",
      "description": "Cash down payment (default 0).",
      "examples": [
        5000
      ]
    },
    "tradeInValue": {
      "type": "number",
      "description": "Trade-in credit (default 0).",
      "examples": [
        0
      ]
    },
    "salesTaxPct": {
      "type": "number",
      "description": "Sales tax percent applied to price (default 0).",
      "examples": [
        6
      ]
    },
    "annualRatePct": {
      "type": "number",
      "description": "Annual nominal rate in percent.",
      "examples": [
        5
      ]
    },
    "termMonths": {
      "type": "number",
      "description": "Term in months.",
      "examples": [
        60
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}