Loan amortization schedule API

Full month-by-month loan amortization: payment, principal vs interest, and running balance, plus totals. Answers 'amortization schedule for this loan', 'how much interest will I pay', 'principal vs interest breakdown'.

Price$0.01per request

MethodPOST

Route/v1/finance/amortization

StatusLive

MIME typeapplication/json

Rate limit120/minute

CacheNo cache

financeloanamortizationmortgagescheduleinterest

API URLhttps://x402.hexl.dev/v1/finance/amortization

Integration docs

Example request

{
  "principal": 250000,
  "annualRate": 0.06,
  "months": 360
}

Example response

{
  "monthlyPayment": 1498.88,
  "totalPaid": 539595.47,
  "totalInterest": 289595.47,
  "months": 360,
  "schedule": [
    {
      "month": 1,
      "payment": 1498.88,
      "principal": 248.88,
      "interest": 1250,
      "balance": 249751.12
    }
  ]
}

Input schema

{
  "type": "object",
  "required": [
    "principal",
    "annualRate",
    "months"
  ],
  "properties": {
    "principal": {
      "type": "number"
    },
    "annualRate": {
      "type": "number"
    },
    "months": {
      "type": "number",
      "minimum": 1,
      "maximum": 1200
    }
  }
}

Output schema

{
  "type": "object",
  "required": [
    "monthlyPayment",
    "totalPaid",
    "totalInterest",
    "schedule"
  ],
  "properties": {
    "monthlyPayment": {
      "type": "number"
    },
    "totalPaid": {
      "type": "number"
    },
    "totalInterest": {
      "type": "number"
    },
    "months": {
      "type": "number"
    },
    "schedule": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": true
      }
    }
  }
}