---
title: "4% Rule Safe Withdrawal Rate Calculator"
method: POST
path: "/v1/tools/calculate_safe_withdrawal_rate"
tags: ["safe withdrawal rate", "4% rule", "FIRE", "retirement", "SWR", "sequence risk", "Guyton-Klinger"]
---

# 4% Rule Safe Withdrawal Rate Calculator

`POST /v1/tools/calculate_safe_withdrawal_rate`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/calculate_safe_withdrawal_rate`
- Auth: none declared

Models whether a retirement portfolio can sustain a given withdrawal rate. Goes beyond the simple 4% rule to show how portfolio composition, inflation, and sequence risk affect the actual safe rate.

**Tool URL:** https://ainumbers.co/tools/170-safe-withdrawal-rate-calculator.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `portfolio_value` number, required: Current portfolio value in USD
  - `annual_withdrawal` number, required: Planned annual withdrawal in USD
  - `horizon_years` number, required: Retirement horizon in years
  - `allocation` string: Portfolio allocation preset
  - `inflation_pct` number: Assumed annual inflation rate
  - `additional_income` number: Annual income from Social Security or pension
  - `strategy` string: Withdrawal strategy

## Response `200`

Successful tool execution result

- object
  - `swr_pct` number
  - `fire_number` number
  - `survival_probability_pct` number
  - `years_to_depletion` number
  - `real_value_at_30yr` number
  - `verdict` string

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)