Mortgage Calculator API POST

Mortgage Calculator is a simple tool for calculating mortgage payments. It returns the monthly payment, total interest, and more.

Try it — live request, no key required

Request

POSTapi.apiverve.com/v1/mortgagecalculator

Verification

Format

No key required to try it. Get a key to use it in your app.

200 OK

{
  "status": "ok",
  "error": null,
  "data": {
    // Mortgage Calculator response payload
  }
}

About the Mortgage Calculator API

Mortgage Calculator works by using the loan amount, interest rate, and loan term to calculate the monthly mortgage payment, total interest, and more.

What people use it for

Real Estate: Calculate mortgage payments by using the Mortgage Calculator API. Use the data to estimate monthly payments and total interest for real estate transactions
Financial Planning: Plan financial budgets by using the Mortgage Calculator API to calculate mortgage payments. Use the data to manage expenses and savings
Home Buying: Estimate mortgage payments by using the Mortgage Calculator API. Use the data to determine affordability and budget for home purchases
Loan Analysis: Analyze loan terms by using the Mortgage Calculator API to calculate mortgage payments. Use the data to compare loan options and choose the best one

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use Mortgage Calculator

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the Mortgage Calculator API.

Read the docs →

What does the Mortgage Calculator API do?

Mortgage Calculator is a simple tool for calculating mortgage payments. It returns the monthly payment, total interest, and more.

How do I authenticate Mortgage Calculator API requests?

Pass your API key in the x-api-key header over HTTPS. One key works across all 300+ APIVerve APIs — there are no per-endpoint credentials.

How much does the Mortgage Calculator API cost?

Each call spends 2 credits from your shared pool. The free tier includes 200 credits every month, and paid plans add more headroom.

How fast is the Mortgage Calculator API?

Response time depends on the endpoint — the p50 through p99 latency for this API is published on this page. Requests are served over HTTPS through a global edge network.

What response formats does the Mortgage Calculator API support?

JSON by default, plus XML and YAML via the format parameter. GraphQL and an MCP interface for AI agents are available across the catalog.

What HTTP method does the Mortgage Calculator API use?

POST over HTTPS, following standard REST conventions with a consistent { status, error, data } response envelope.

Request parameters — POST /v1/mortgagecalculator

Sent as JSON in the request body. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Parameter	Type	Example	Description
`amount`Required	number	`200000`	The loan amount range 0-inf
`rate`Required	number	`4.5`	The interest rate (percentage) range 0-100
`years`Required	integer	`30`	The loan term in years range 1-50

Optional

Parameter	Type	Example	Description
`downpayment`Optional	number	`15000`	The down payment amount range 0-inf
`annual_propertytax`Optional	number	`2000`	The annual property tax amount range 0-inf
`annual_homeinsurance`Optional	number	`1200`	The annual home insurance amount range 0-inf
`annual_hoa`Optional	number	`500`	The annual HOA amount range 0-inf

Example request

curl -X POST "https://api.apiverve.com/v1/mortgagecalculator" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount":570000,"rate":6.8,"years":30,"downpayment":1,"annual_propertytax":1,"annual_homeinsurance":1,"annual_hoa":1}'

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.
`content-type`Required	POST body	`application/json`

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — POST /v1/mortgagecalculator

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "amount": 570000,
    "downpayment": 0,
    "rate": 6.8,
    "years": 30,
    "total_interest_paid": 767750.49,
    "total_loan_payment": 1337750.49,
    "interestRatio": 57.39,
    "monthly_payment": {
      "total": 3715.97,
      "mortgage": 3715.97,
      "property_tax": 0,
      "hoa": 0,
      "home_insurance": 0
    },
    "annual_payment": {
      "total": 44591.68,
      "mortgage": 44591.68,
      "property_tax": 0,
      "hoa": 0,
      "home_insurance": 0
    },
    "formatted": {
      "amount": "$570,000",
      "monthlyPayment": "$3,715.97",
      "totalInterestPaid": "$767,750.49",
      "totalLoanPayment": "$1,337,750.49"
    },
    "amortization_schedule": [
      {
        "month": 1,
        "interest_payment": 3230,
        "principal_payment": 485.97,
        "remaining_balance": 569514.03
      },
      {
        "month": 2,
        "interest_payment": 3227.25,
        "principal_payment": 488.73,
        "remaining_balance": 569025.3
      },
      {
        "month": 3,
        "interest_payment": 3224.48,
        "principal_payment": 491.5,
        "remaining_balance": 568533.8
      }
    ]
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`amount`	number	`570000`	Loan amount in dollars
`downpayment`	number	`0`	Down payment amount provided
`rate`	number	`6.8`	Interest rate percentage used for calculation
`years`	number	`30`	Loan term in years
`total_interest_paid`Premium	number	`767750.49`	Total interest paid over entire loan term
`total_loan_payment`Premium	number	`1337750.49`	Total amount paid (principal + interest)
`interestRatio`Premium	number	`57.39`	Percentage of payment that is interest
`monthly_payment`	object	`{...}`
`total`	number	`3715.97`	Total monthly payment including all fees
`mortgage`	number	`3715.97`	Monthly mortgage payment (principal + interest)
`property_tax`	number	`0`	Monthly property tax portion of payment
`hoa`	number	`0`	Monthly HOA fee portion of payment
`home_insurance`	number	`0`	Monthly home insurance portion of payment
`annual_payment`	object	`{...}`
`total`	number	`44591.68`	Total annual payment including all fees
`mortgage`	number	`44591.68`	Annual mortgage payment (principal + interest)
`property_tax`	number	`0`	Annual property tax portion of payment
`hoa`	number	`0`	Annual HOA fee portion of payment
`home_insurance`	number	`0`	Annual home insurance portion of payment
`formatted`	object	`{...}`
`amount`	string	`"$570,000"`	Formatted loan amount with currency symbol
`monthlyPayment`	string	`"$3,715.97"`	Formatted monthly payment with currency
`totalInterestPaid`	string	`"$767,750.49"`	Formatted total interest paid with currency
`totalLoanPayment`	string	`"$1,337,750.49"`	Formatted total loan payment with currency
`amortization_schedule`Premium	array[3]		Month-by-month loan repayment schedule breakdown
`month`Premium	number	`1`	Payment month number in loan term
`interest_payment`Premium	number	`3230`	Interest portion of monthly payment
`principal_payment`Premium	number	`485.97`	Principal portion of monthly payment
`remaining_balance`Premium	number	`569514.03`	Outstanding loan balance after payment

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	Mortgage Calculator calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — POST /v1/mortgagecalculator

No SDK to install — this is a plain HTTPS call to /v1/mortgagecalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/mortgagecalculator" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/mortgagecalculator-apiSource, issues and the examples this page is built from.ReferenceMortgage Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/mortgagecalculatornpm apiverve-mortgagecalculatorPyPI APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — POST /v1/mortgagecalculator

Install the Node.js SDK, then call the Mortgage Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/mortgagecalculator

Node.js

const res = await fetch("https://api.apiverve.com/v1/mortgagecalculator", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/mortgagecalculatorThe published Node.js client, versioned and signed.GitHubapiverve/mortgagecalculator-apiSource, issues and the examples this page is built from.ReferenceMortgage Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

apiverve-mortgagecalculatorPyPI APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — POST /v1/mortgagecalculator

Install the Python SDK, then call the Mortgage Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — PyPI

pip install apiverve-mortgagecalculator

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/mortgagecalculator",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

PyPIapiverve-mortgagecalculatorThe published Python client, versioned and signed.GitHubapiverve/mortgagecalculator-apiSource, issues and the examples this page is built from.ReferenceMortgage Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/mortgagecalculatornpm APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — POST /v1/mortgagecalculator

Install the C# / .NET SDK, then call the Mortgage Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.MortgageCalculator

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/mortgagecalculator");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.MortgageCalculatorThe published C# / .NET client, versioned and signed.GitHubapiverve/mortgagecalculator-apiSource, issues and the examples this page is built from.ReferenceMortgage Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/mortgagecalculatornpm apiverve-mortgagecalculatorPyPI

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — POST /v1/mortgagecalculator

No SDK to install — this is a plain HTTPS call to /v1/mortgagecalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/mortgagecalculator", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/mortgagecalculatornpm apiverve-mortgagecalculatorPyPI APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — POST /v1/mortgagecalculator

No SDK to install — this is a plain HTTPS call to /v1/mortgagecalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/mortgagecalculator");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/mortgagecalculatornpm apiverve-mortgagecalculatorPyPI APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — POST /v1/mortgagecalculator

No SDK to install — this is a plain HTTPS call to /v1/mortgagecalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/mortgagecalculator")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/mortgagecalculatornpm apiverve-mortgagecalculatorPyPI APIVerve.API.MortgageCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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Mortgage Calculator API POST

Try it — live request, no key required

About the Mortgage Calculator API

What people use it for

Ways to call it

Other ways to use Mortgage Calculator

Questions.

Request parameters — POST /v1/mortgagecalculator

Required

Optional

Authentication

Response — POST /v1/mortgagecalculator

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — POST /v1/mortgagecalculator

Resources

Also published for

Call it from Node.js — POST /v1/mortgagecalculator

Resources

Also published for

Call it from Python — POST /v1/mortgagecalculator

Resources

Also published for

Call it from C# / .NET — POST /v1/mortgagecalculator

Resources

Also published for

Call it from Go — POST /v1/mortgagecalculator

Resources

Also published for

Call it from PHP — POST /v1/mortgagecalculator

Resources

Also published for

Call it from Ruby — POST /v1/mortgagecalculator

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — Mortgage Calculator API

Finance

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