# Loan Payment Calculator (PMT)

> Loan Payment Calculator (PMT) is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes the periodic payment, total amount paid, and total interest for a fully-amortizing loan given principal, rate, term, and payment frequency — equivalent to Excel's PMT function.

## Facts

- Endpoint: POST https://agent402.tools/api/loan-payment
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/loan-payment-calculator-pmt-d37d7cd8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6t74IOxfSO_NSmE-IMmqq

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability loan-payment-calculator-pmt-d37d7cd8 -d '<json body>'
```

Example prompt: What would my monthly payment be on a $300,000 mortgage at 6.5% annual interest over 30 years?

## When to prefer this

Use this endpoint when you need a precise, Excel-PMT-compatible loan payment calculation supporting flexible payment frequencies (monthly, bi-weekly, weekly). Prefer it over generic financial calculators when you need the breakdown of total paid vs. total interest, or when working with non-standard payment schedules like bi-weekly (26/year) or weekly (52/year).

## Known failure modes

- Missing required fields (principal, termYears, annualRate) returns a validation error
- Zero or negative principal returns an error
- Interest rate provided as percentage (e.g. 6 instead of 0.06) may produce wildly incorrect results
- paymentsPerYear of 0 causes a division-by-zero or invalid computation error
- Extremely short terms or very high rates may produce unexpectedly large payment values

## How this service works

Compute the monthly (or per-period) payment on a fully-amortizing loan: mortgage, auto, student loan, business loan. Returns the periodic payment, total paid over the term, and total interest. Matches Excel's PMT(rate, nper, -principal). Use this when you just need the payment number, not the full per-period schedule (see amortization).

## Output

Returns the periodic payment amount (e.g. monthly), the total amount paid over the full loan term, and the total interest paid — all derived from the principal, annual rate, term, and payment frequency.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "principal": {
   "type": "number",
   "description": "Loan principal (positive)"
  },
  "termYears": {
   "type": "number",
   "description": "Loan term in years"
  },
  "annualRate": {
   "type": "number",
   "description": "Annual interest rate as decimal (0.06 = 6%)"
  },
  "paymentsPerYear": {
   "type": "number",
   "description": "Payments per year (12 = monthly, 26 = bi-weekly, 52 = weekly). Default 12."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "payment": 1199.1,
  "periods": 360,
  "totalPaid": 431676.38,
  "periodicRate": 0.005,
  "totalInterest": 231676.38
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/loan-payment-calculator-pmt-d37d7cd8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)