# Coast FIRE Calculator

> Coast FIRE Calculator is a paid API for AI agents from x402.outpimp.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Computes the coast FIRE lump sum needed today to reach your retirement number by a target age, plus a year-by-year projection of when your savings trajectory crosses that threshold given ongoing contributions.

## Facts

- Endpoint: POST https://x402.outpimp.com/coastFireCalculator
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/coast-fire-calculator-22314161
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UAh4Tl_VtCuzrInkUaVIK

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 coast-fire-calculator-22314161 -d '<json body>'
```

Example prompt: I'm 38 years old with $250,000 saved, plan to retire at 67 spending $70,000 per year, and I contribute $1,500 per month — can you calculate my coast FIRE number and show me a year-by-year projection of when my savings will cross that threshold?

## When to prefer this

Choose this endpoint when you need to determine the specific lump sum required today to 'coast' to retirement without further contributions, or want a year-by-year timeline of when ongoing savings cross that coast FIRE threshold. Ideal for FIRE-planning agents, personal finance assistants, or retirement readiness dashboards. Prefer this over generic compound-interest calculators when the user's goal is specifically the coast FIRE strategy — combining a target retirement spending figure with a safe withdrawal rate to derive the required nest egg and working backwards to today's required balance.

## Known failure modes

- Missing required fields (currentAge, currentNetWorth, retirementAnnualSpending) return validation errors
- Unrealistic input values (e.g. retirementAge less than currentAge) may produce nonsensical output
- Very high investment return rates or very long time horizons may produce extreme projections
- Payment failure (x402 protocol) if USDC balance is insufficient

## How this service works

Coast FIRE calculator. Computes the lump sum needed today, invested with zero further contributions, to grow into your full retirement number by your target retirement age, plus (given an ongoing monthly contribution) a year-by-year projection of when your actual trajectory crosses that lump sum.

## Output

Returns the coast FIRE lump sum required today (the amount that, invested with no further contributions, grows to fully fund retirement by the target age), and a year-by-year table showing projected net worth alongside the coast FIRE threshold, indicating the crossover year when ongoing contributions make further saving optional.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "swr": {
   "type": "number",
   "default": 0.04,
   "description": "Safe withdrawal rate, as a fraction. Default 0.04."
  },
  "currentAge": {
   "type": "number",
   "description": "Your current age in years."
  },
  "inflationRate": {
   "type": "number",
   "default": 0.03,
   "description": "Expected annual inflation rate, as a fraction. Default 0.03."
  },
  "retirementAge": {
   "type": "number",
   "default": 67,
   "description": "Target traditional retirement age. Default 67."
  },
  "currentNetWorth": {
   "type": "number",
   "description": "Current invested net worth."
  },
  "monthlyContribution": {
   "type": "number",
   "default": 0,
   "description": "Ongoing monthly contribution toward currentNetWorth. Default 0."
  },
  "investmentReturnRate": {
   "type": "number",
   "default": 0.07,
   "description": "Expected annual investment return, as a fraction. Default 0.07."
  },
  "retirementAnnualSpending": {
   "type": "number",
   "description": "Expected annual spending in retirement."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coast-fire-calculator-22314161/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.outpimp.com](https://www.zero.xyz/host/x402.outpimp.com/llms.txt)