---
type: guide
title: "Postcard Sizes Explained From 3x5 to 6x9"
description: "Every postcard size explained, from 3x5 to 6x9, with the right pick for mailing and USPS rules. Order custom postcards from 4OVER4."
resource: https://www.4over4.com/guide/postcard-sizes-the-complete-guide
tags: ["guide"]
timestamp: 2026-08-08T21:25:50.722Z
---

# Postcard Sizes Explained From 3x5 to 6x9

Every postcard size explained, from 3x5 to 6x9, with the right pick for mailing and USPS rules. Order custom postcards from 4OVER4.

See [all guide concepts](index.md).

- Page type: guide
- URL: https://www.4over4.com/guide/postcard-sizes-the-complete-guide