{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://askcalculators.com/calculator/interest-only-mortgage-calculator/schema.json",
  "title": "Interest Only Mortgage Calculator inputs",
  "description": "Estimate payments and total interest for a mortgage with an initial interest-only period followed by amortizing payments.",
  "type": "object",
  "properties": {
    "loanAmount": {
      "title": "Mortgage principal",
      "type": "number",
      "default": 400000,
      "minimum": 0.01,
      "x-step": 1000,
      "multipleOf": 1000,
      "x-unit": "currency"
    },
    "annualRate": {
      "title": "Annual interest rate",
      "type": "number",
      "default": 6.5,
      "minimum": 0,
      "maximum": 100,
      "x-step": 0.01,
      "x-unit": "percent"
    },
    "totalTermYears": {
      "title": "Total mortgage term in years",
      "type": "number",
      "default": 30,
      "minimum": 1,
      "maximum": 50,
      "x-step": 1,
      "multipleOf": 1
    },
    "interestOnlyYears": {
      "title": "Interest-only years",
      "type": "number",
      "default": 10,
      "minimum": 0,
      "maximum": 49,
      "x-step": 1,
      "multipleOf": 1
    }
  },
  "required": [
    "loanAmount",
    "annualRate",
    "totalTermYears",
    "interestOnlyYears"
  ],
  "additionalProperties": false,
  "x-askcalculators": {
    "version": "1.0.0",
    "calculatorUrl": "https://askcalculators.com/calculator/interest-only-mortgage-calculator/",
    "queryExample": "https://askcalculators.com/calculator/interest-only-mortgage-calculator/?loanAmount=400000&annualRate=6.5&totalTermYears=30&interestOnlyYears=10",
    "migrationStatus": "new",
    "reviewStatus": "pending",
    "pageStatus": "live",
    "workStatus": "pending",
    "formula": {
      "expression": "interest-only payment = principal × annual rate ÷ 12; remaining principal is amortized over the remaining term"
    },
    "quality": {
      "availability": "live",
      "technicalReviewRecord": "/reviews/interest-only-mortgage-calculator.json",
      "qualifiedReview": "pending",
      "qualifiedReviewer": null,
      "qualifiedReviewDate": null,
      "formulaVersion": "1.0.0",
      "referenceCoverage": "references-pending",
      "releaseTestScope": "Catalog and regression checks are not a professional formula audit; consult release evidence.",
      "historicalMetadataDate": "2026-09-01",
      "historicalMetadataNotice": "The imported date is not evidence of a completed human review."
    },
    "outputs": {
      "interestOnlyPayment": {
        "title": "Monthly interest-only payment",
        "type": "number",
        "x-format": "currency",
        "x-primary": true
      },
      "amortizingPayment": {
        "title": "Monthly payment after interest-only period",
        "type": "number",
        "x-format": "currency"
      },
      "paymentIncrease": {
        "title": "Payment increase",
        "type": "number",
        "x-format": "currency"
      },
      "totalInterest": {
        "title": "Total interest over full term",
        "type": "number",
        "x-format": "currency"
      },
      "totalPaid": {
        "title": "Total paid",
        "type": "number",
        "x-format": "currency"
      }
    }
  }
}