https://pe.usps.com/BusinessMail101?ViewName=Cards

But to qualify for mailing at the First-Class Mail postcard price, it must be: ... price for postcards, so you don't have to worry about your postcard being too big ...

https://www.papersizes.org/postcard-sizes.htm

Postcard sizes explained, together with maximum and minimum dimensions ... International maximum size is considerably bigger than the USPS maximum size.

https://www.uprinting.com/standard-postcard-size.html

Celebrate special occasions with Standard Postcards. Learn about the different Postcard sizes & choose the best option for your printing & design.

https://toughnickel.com/industries/Postcard-Size-Guide

Apr 11, 2018 ... This postcard size guide covers the standard postcard size, optional larger postcard sizes, ... Instead, you can make a bigger postcard! (I know ...

https://www.printplace.com/articles/standard-postcard-sizes

What are the standard postcard sizes for mailing and EDDM®? We have the answer to this question and more in this guide to printing and mailing postcards.

https://blog.mailing.com/simple-guidelines-for-usps-postcard-rate-size-

Jun 14, 2018 ... USPS Postcard rate and size guidelines can get tricky. But we're here to ... Need a "big picture" USPS direct mail breakdown? Head over to our ...

http://www.subtlenetwork.com/what-is-the-best-size-of-a-postcard.html

If you are going to invest time and money into a postcard marketing campaign, ... Your postcard can't be bigger than 6 inches by 11.5 inches by .25 inches thick.

http://designerstoolbox.com/designresources/postcards/

All measurements are in inches. These are standard postcard sizes. Check with United States Post Office before mailing. Designers Toolbox is not responsible ...

https://www.stamps.com/usps/postcards/

To qualify for the base rate, postcards cannot be folded. Large postcards can measure up to 6 ⅛” high, 11 ½” long and ¼” thick, but they cost as much as a ...

https://www.summitprintingpro.com/resources/postcard-specs.html

Postcard USPS postal requirements & specifications for automated mailing ... Big news in the mailing business, the United States Postal Service (USPS)