# agent402.tools Effective Annual Rate Calculator

> agent402.tools Effective Annual Rate 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).

Converts a nominal annual rate (APR) compounded m times per year into the effective annual rate (EAR/APY), supporting both periodic and continuous compounding.

## Facts

- Endpoint: POST https://agent402.tools/api/effective-annual-rate
- 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/agent402-tools-effective-annual-rate-calculator-c81002ff
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wSAXHD-6hJrKmJ_bfff2v

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 agent402-tools-effective-annual-rate-calculator-c81002ff -d '<json body>'
```

Example prompt: What's the effective annual rate (APY) on a loan with a 7.5% nominal APR compounded monthly — can you calculate that for me?

## When to prefer this

Use this endpoint when you need a precise mathematical conversion from nominal APR to effective annual rate (EAR/APY), especially when comparing financial products with different compounding frequencies or when handling continuous compounding scenarios.

## Known failure modes

- Missing nominalAnnualRate field returns a validation error
- Invalid or non-numeric rate/compounding values cause a 400 error
- compoundingPerYear of zero causes division-by-zero error
- Payment failure or insufficient USDC balance returns 402 Payment Required

## How this service works

Convert a nominal annual rate (APR) compounded m times per year into the effective annual rate (EAR / APY): (1 + apr/m)^m - 1. Set continuous:true for e^apr - 1.

## Output

Returns the effective annual rate (EAR/APY) as a decimal, computed from the formula (1 + apr/m)^m - 1 for periodic compounding, or e^apr - 1 for continuous compounding.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "continuous": {
   "type": "boolean",
   "description": "If true, use continuous compounding (e^apr - 1)."
  },
  "nominalAnnualRate": {
   "type": "number",
   "description": "Nominal annual rate / APR as decimal"
  },
  "compoundingPerYear": {
   "type": "number",
   "description": "Compounding periods per year. Default 12."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "nominalAnnualRate": 0.12,
  "compoundingPerYear": 12,
  "effectiveAnnualRate": 0.126825
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-effective-annual-rate-calculator-c81002ff/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)