---
title: "Debt Payoff Calculator: Avalanche vs Snowball"
method: POST
path: "/api/v1/tools/debt-payoff-calculator"
tags: ["debt"]
---

# Debt Payoff Calculator: Avalanche vs Snowball

`POST /api/v1/tools/debt-payoff-calculator`

## Request

- Base URL: `https://calcfleet.com`
- URL: `https://calcfleet.com/api/v1/tools/debt-payoff-calculator`
- Auth: none declared

Compare the avalanche and snowball debt payoff strategies side by side. See how much interest you save and how many months sooner you'll be debt-free.

## Request body

- object
  - `debts` object[], required
    - `name` string, required
    - `balance` number, required
    - `aprPct` number, required
    - `minPayment` number, required
  - `extraMonthly` number, required
  - `strategy` 'avalanche' | 'snowball', required

## Response `200`

Successful calculation result.

- object
  - `result` object, required: Structured calculation output (fields vary per calculator).

## Other responses

- `400`: Invalid input — the issues array contains Zod validation errors.
- `403`: Forbidden — an Authorization: Bearer cf_… key was supplied but is invalid.
- `404`: Unknown tool slug.

---

[API](https://skmtc.dev/calcfleet/apis/calcfleet-financial-calculators-api.md) · [All operations](https://skmtc.dev/calcfleet/apis/calcfleet-financial-calculators-api/llms.txt) · [OpenAPI document](https://skmtc.dev/calcfleet/apis/calcfleet-financial-calculators-api/revisions/cd9abd595bbe?raw)