Free Finance Calculator API | FinanceCalcsHub.com

🧭 Overview

The FinanceCalcsHub API lets you compute EMI, compound interest, SIP returns, mortgage repayments, GST, income tax, inflation, and more — all via simple GET requests. No registration, no API key, no fees.

Every response returns a structured JSON object with the calculated result, a human-readable breakdown, and formula metadata so you can attribute the computation correctly.

ℹ️

All calculations run server-side using the same formulas that power the on-page calculators. Results are identical — you're getting the exact same engine via API.

🔗 Base URL

GET https://api.financecalcshub.com/v2/

All endpoints are append-only paths from this base. Example: https://api.financecalcshub.com/v2/emi?principal=500000&rate=8.5&tenure=60

🔐 Authentication

✅

No API key needed. All endpoints are publicly accessible. For attribution, please link back to financecalcshub.com — that's the only ask.

If you plan to exceed 500 requests/minute or use the API in a commercial product, reach out via the contact page for a partnership arrangement.

⚡ Rate Limits

Tier	Limit	Notes
Free	200 req / min	Default. No auth required.
Partner	5,000 req / min	Email us for a partner key.
Self-hosted	Unlimited	Clone the open-source repo.

Exceeding the free limit returns 429 Too Many Requests with a Retry-After header.

📡 All Endpoints

GET/emi

FREE

EMI calculation for loans, mortgages, and credit with amortization schedule

GET/compound-interest

FREE

Compound interest with configurable compounding frequency (daily/monthly/yearly)

GET/sip

FREENEW

Systematic Investment Plan returns with CAGR and wealth gain breakdown

GET/mortgage

FREE

Mortgage repayment, total interest, and full amortization table

GET/roi

FREE

Return on Investment with annualized CAGR calculation

GET/income-tax

FREENEW

Income tax estimate for India (old & new regime), UK, and US brackets

GET/gst

FREE

GST / VAT calculation — inclusive or exclusive modes

GET/inflation

FREE

Future value of money adjusted for inflation over years

💳 EMI Calculator

Calculates the Equated Monthly Instalment for any loan with principal, annual rate, and tenure in months.

GET /v2/emi

Parameter	Type	Required	Description
principal	number	required	Loan amount in any currency
rate	number	required	Annual interest rate in percent (e.g. `8.5` = 8.5%)
tenure	integer	required	Loan duration in months
currency	string	optional	Currency symbol in response (default: `INR`). Accepts `USD`, `GBP`, `SAR`
schedule	boolean	optional	Include full amortization schedule (default: `false`)

{
  "status": "success",
  "calculator": "emi",
  "inputs": {
    "principal": 500000,
    "rate": 8.5,
    "tenure_months": 60,
    "currency": "INR"
  },
  "result": {
    "monthly_emi": 10247.53,
    "total_payment": 614851.8,
    "total_interest": 114851.8,
    "principal_percentage": 81.32,
    "interest_percentage": 18.68
  },
  "formula": "EMI = P × r × (1+r)^n / ((1+r)^n - 1)",
  "attribution": "financecalcshub.com"
}

{
  "status": "error",
  "code": 400,
  "message": "Missing required parameter: principal",
  "docs": "https://financecalcshub.com/api#emi"
}

⚡ Live API Tester — EMI Results are simulated demo responses

Principal (loan amount)

Annual Rate (%)

Tenure (months)

Currency

Click "Run Request" to see a live response ↑

📈 Compound Interest

GET/v2/compound-interest

Parameter	Type	Required	Description
principal	number	required	Initial investment amount
rate	number	required	Annual interest rate (%)
years	integer	required	Investment duration in years
frequency	string	optional	`daily` \| `monthly` \| `quarterly` \| `annually` (default: monthly)

example request

GET /v2/compound-interest?principal=100000&rate=12&years=5&frequency=monthly

Response:
{
  "result": {
    "future_value": 181669.67,
    "interest_earned": 81669.67,
    "growth_multiple": 1.82,
    "effective_annual_rate": 12.68
  }
}

📊 SIP Returns

GET/v2/sip

Parameter	Type	Required	Description
monthly_investment	number	required	Amount invested every month
rate	number	required	Expected annual return rate (%)
years	integer	required	Investment tenure in years

💻 Code Examples

javascript · fetch

// EMI Calculator API — JavaScript
const calculateEMI = async (principal, rate, tenure) => {
  const url = new URL('https://api.financecalcshub.com/v2/emi');
  url.searchParams.set('principal', principal);
  url.searchParams.set('rate', rate);
  url.searchParams.set('tenure', tenure);

  const res = await fetch(url);
  const data = await res.json();

  if (data.status === 'success') {
    console.log(`Monthly EMI: ₹${data.result.monthly_emi}`);
    console.log(`Total Interest: ₹${data.result.total_interest}`);
    return data.result;
  }
};

// Usage
calculateEMI(500000, 8.5, 60);

// Attribution (required in UI)
// Powered by <a href="https://financecalcshub.com">FinanceCalcsHub</a>

python · requests

import requests

def calculate_emi(principal, rate, tenure, currency="INR"):
    url = "https://api.financecalcshub.com/v2/emi"
    params = {
        "principal": principal,
        "rate": rate,
        "tenure": tenure,
        "currency": currency
    }
    response = requests.get(url, params=params)
    data = response.json()

    if data["status"] == "success":
        result = data["result"]
        print(f"Monthly EMI: {result['monthly_emi']}")
        print(f"Total Interest: {result['total_interest']}")
        return result

# Usage
emi_data = calculate_emi(500000, 8.5, 60)

php · curl

<?php
function calculateEMI($principal, $rate, $tenure) {
    $url = 'https://api.financecalcshub.com/v2/emi?'
        . http_build_query([
            'principal' => $principal,
            'rate'      => $rate,
            'tenure'    => $tenure,
        ]);

    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $response = curl_exec($ch);
    curl_close($ch);

    $data = json_decode($response, true);

    if ($data['status'] === 'success') {
        return $data['result'];
    }
}

$result = calculateEMI(500000, 8.5, 60);
echo "EMI: ₹" . $result['monthly_emi'];

curl · terminal

# Basic EMI request
curl "https://api.financecalcshub.com/v2/emi?principal=500000&rate=8.5&tenure=60"

# Pretty-print JSON (requires jq)
curl "https://api.financecalcshub.com/v2/emi?principal=500000&rate=8.5&tenure=60" | jq

# SIP with currency
curl "https://api.financecalcshub.com/v2/sip?monthly_investment=5000&rate=12&years=10"

# GST inclusive
curl "https://api.financecalcshub.com/v2/gst?amount=1000&rate=18&mode=inclusive"

🚨 Error Codes

Code	Meaning	Fix
200	OK	Calculation succeeded.
400	Bad Request	Missing or invalid parameter. Check the error message field.
404	Not Found	Unknown endpoint. Check the endpoint path.
429	Too Many Requests	Rate limit hit. Slow down or request a partner key.
500	Server Error	Contact us. Temporary issue on our end.

🙏 Attribution

⚠️

When embedding results from this API in a public-facing product, please include a small attribution link: Powered by financecalcshub.com. This is how we keep the API free forever — backlinks are our only currency.

html · attribution snippet

<a href="https://financecalcshub.com" 
   target="_blank" 
   rel="noopener"
   style="font-size:12px;opacity:0.7">
  Powered by FinanceCalcsHub
</a>