# Annuity Present & Future Value Calculator

> Annuity Present & Future Value Calculator is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Calculates the present value and future value of a level annuity (ordinary or annuity-due) given a periodic payment, number of periods, and interest rate per period.

## Facts

- Endpoint: POST https://agent402.tools/api/annuity
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/annuity-present-future-value-calculator-6ad8d1aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4r6pxiHwjS6Mmwz0Tlv41

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 annuity-present-future-value-calculator-6ad8d1aa -d '<json body>'
```

Example prompt: What's the present value and future value of an ordinary annuity paying $500 per month for 60 periods at a rate of 0.5% per period?

## When to prefer this

Use this endpoint when you need a fast, inexpensive computation of annuity present or future value given fixed periodic payments — especially when you want to distinguish between ordinary annuity and annuity-due structures. Prefer this over manual calculation or general-purpose math tools when the x402 micropayment model is already in use.

## Known failure modes

- Missing required fields (payment, periods, ratePerPeriod) return a 400 error
- Non-positive or non-integer periods value causes a validation error
- Invalid annuity type string (not 'ordinary' or 'due') may default to ordinary or return an error
- Negative interest rate may produce unexpected or undefined results
- Payment of zero returns trivial zero values

## How this service works

Present and future value of a level annuity (equal periodic payments). Supports an ordinary annuity (payments at period end) and an annuity-due (payments at period start).

## Output

Returns the present value (PV) and future value (FV) of the specified level annuity, computed using standard time-value-of-money formulas for either an ordinary annuity (payments at end of period) or an annuity-due (payments at start of period).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "type": {
   "type": "string",
   "description": "\"ordinary\" (end) or \"due\" (start). Default ordinary."
  },
  "payment": {
   "type": "number",
   "description": "Payment per period (PMT)"
  },
  "periods": {
   "type": "number",
   "description": "Number of payments (positive integer)"
  },
  "ratePerPeriod": {
   "type": "number",
   "description": "Interest rate per period as decimal"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "ordinary",
  "futureValue": 1257.79,
  "presentValue": 772.17
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/annuity-present-future-value-calculator-6ad8d1aa/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)