$Loan / Installment Calculation$

Loan / Installment Calculation

Finance Math & Calculations Credits / request: 1

Calculates equal installments, total interest and an optional schedule.

GET https://api.apikodu.com/api/v1/math/loan

Documentation

Overview

Equal-installment (annuity) loan.

Authentication

Every request requires the x-api-key header. Credits used and remaining quota are returned in response headers (x-api-credits-used, x-api-remaining-credits, x-rate-limit-*).

Request

GET https://api.apikodu.com/api/v1/math/loan?amount=100000&rate=24&termMonths=12&includeSchedule=true

GET query or POST JSON.

Parameters

Name	Type	Required	Default	Options	Description
`amount`	number	* Required	—	—	Principal.
`rate`	number	* Required	—	—	Annual interest %.
`termMonths`	integer	* Required	—	—	Term 1–360 months.
`currency`	string	Optional	—	—	ISO code.
`includeSchedule`	boolean	Optional	`true`	`true` `false`	Installment schedule.

Response

Name	Type	Description
`amount`	number	Principal. 2 decimals.
`rate`	number	Annual interest rate (%).
`termMonths`	integer	Term in months.
`amountPayment`	number	Fixed monthly installment (annuity). 2 decimals.
`amountInterest`	number	Total interest paid over the term.
`amountTotal`	number	Principal + total interest. amountPayment * termMonths.
`currency`	string	ISO currency code. Null if omitted.
`schedule`	array	Installment rows when includeSchedule=true. Empty array when false.
`schedule[].index`	integer	Installment number (1 to termMonths).
`schedule[].amountPayment`	number	Payment this month (principal + interest).
`schedule[].amountPrincipal`	number	Principal portion of this installment.
`schedule[].amountInterest`	number	Interest portion of this installment.
`schedule[].amountRemaining`	number	Remaining principal after this installment.

Errors

HTTP	code	Description
`400`	`-241`	POST body missing, or amount/rate missing or out of range.
`400`	`-248`	termMonths is outside 1–360.
`401`	`-100`	x-api-key is missing, empty, malformed, inactive, banned, expired, IP-restricted, or not allowed for this API.
`429`	`-221`	Per-minute request limit exceeded. Response headers: x-rate-limit-limit, x-rate-limit-remaining, x-rate-limit-reset.
`429`	—	Package credit quota cannot cover this request. Body may be { error, limit, currentUsage, requestCost } (no code field).
`500`	`-1`	Unexpected server error. message is a generic error text without technical details.

Notes

Success body is { data: { ... } }. Error body is { code, message }. code is an ApiResponseCode enum value (negative integer).

Sample response

{
  "data": {
    "amount": 100000.00,
    "rate": 24.0,
    "termMonths": 12,
    "amountPayment": 9455.96,
    "amountInterest": 13471.52,
    "amountTotal": 113471.52,
    "currency": "EUR",
    "schedule": [
      {
        "index": 1,
        "amountPayment": 9455.96,
        "amountPrincipal": 7455.96,
        "amountInterest": 2000.00,
        "amountRemaining": 92544.04
      }
    ]
  }
}

Code samples

  
      const response = await fetch('https://api.apikodu.com/api/v1/math/loan', {
        method: 'GET',
        headers: {
          'x-api-key': 'YOUR_API_KEY'
        }
      });

      const data = await response.json();
      console.log(data);

  
      import requests

      headers = {
          'x-api-key': 'YOUR_API_KEY'
      }

      response = requests.get('https://api.apikodu.com/api/v1/math/loan', headers=headers)
      print(response.json())

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

      var response = await client.GetStringAsync("https://api.apikodu.com/api/v1/math/loan");
      Console.WriteLine(response);

  
      $response = file_get_contents('https://api.apikodu.com/api/v1/math/loan', false, stream_context_create([
          'http' => [
              'header' => "x-api-key: YOUR_API_KEY"
          ]
      ]));

      print_r(json_decode($response, true));

  
      curl -X GET 'https://api.apikodu.com/api/v1/math/loan' \
        -H 'x-api-key: YOUR_API_KEY'

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