Postcard Sizes: USPS Dimensions for 4×6, 5×7 and 6×9 Cards

What is the standard postcard size?

Here are three recent postcards I got in a couple of different sizes. The top one from Bulgaria is a 6 × 4 inch postcard, a common size you'll see in gift shops.

Compare common postcard dimensions

For a standard postcard mailed within the U.S., you can use a postcard stamp if it fits the retail sizes in the table above. Larger cards need more postage when mailed individually. Commercial postcard pricing has separate USPS mailing requirements.

There are also rules about thickness and weight:

• Thickness: 0.007 to 0.016 inch for retail postcard pricing. Commercial postcards over 6 inches long or 4¼ inches high must be at least 0.009 inch thick, with the same 0.016 inch maximum.
• Weight: no more than 3.5 ounces for postcard pricing.

Retail and commercial postcard limits are different

If you're buying a postcard stamp and dropping off a vacation or gift-shop postcard in the U.S., make sure it's no more than 6 inches long and 4¼ inches tall. Larger cards need more postage when mailed individually. For eligible commercial mailings, postcards can be up to 9 inches long and 6 inches tall.

How thick should postcard stock be?

If you're planning on making your own postcard, make sure you're using cardstock between 0.007 and 0.016 inch thick. Commercial postcard mailings can also start at 0.007 inch, but cards over 6 inches long or 4¼ inches high need to be at least 0.009 inch thick.

At The Letter Pilot, we pay close attention to the thickness of our mailings to help prevent them from being returned.

How much postage does each size need?

For a standard 6 × 4 inch postcard mailed within the U.S., you just need a postcard stamp. See our stamp guide for more.

Check a finished sample before printing a batch

• Measure the trimmed card with the address orientation you plan to use.
• Confirm the stock thickness and finished weight.
• Decide whether you are using retail stamps or a provider's eligible commercial mailing service.
• Use the printer's layout template and keep the address, postage and required clear areas available.
• Have USPS or the mailing provider review unusual stock, shapes or attachments before ordering the full batch.