---
title: "Calculate Subscription Upgrade"
method: POST
path: "/api/billing/paypal/calculate-upgrade"
tags: ["PayPal Integration"]
---

# Calculate Subscription Upgrade

`POST /api/billing/paypal/calculate-upgrade`

## Request

- Base URL: `https://api.apitomcp.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.apitomcp.ai/api/billing/paypal/calculate-upgrade`
- Auth: none declared

Calculate prorated billing for subscription upgrade (preview only)

## Request body

- PayPalSubscriptionRequest
  - `plan_id` string, required
  - `billing_cycle` string, required

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/apitomcp/apis/api-to-mcp-platform.md) - [All operations](https://skmtc.dev/apitomcp/apis/api-to-mcp-platform/llms.txt) - [OpenAPI document](https://skmtc.dev/apitomcp/apis/api-to-mcp-platform/revisions/32569c7a994c?raw)