Written by Sabrina Dougall Reviewed by Heleana Neil Updated on March 20, 2023 USPS Flat Rate is one of the best value postage shipping solutions. The service simplifies calculating the costs of mailing your clients and customers, and saves you time and money by reducing the administrative burden of sending your business mail.If you’re not familiar with costs for USPS Flat Rate postage and packaging, read on.USPS Flat Rate Envelope Shipping PricesCurrent USPS Flat Rate Priority Mail envelope prices are:PackagingShipping PriceDimensionsIdeal for…Flat Rate Envelope$7.75(commercial base)$8.95(Post Office)12 1/2″ x 9 1/2″LettersEssaysManuscriptsWindow Flat Rate Envelope$7.75(commercial base)$8.95(Post Office)10″ x 5″or12 1/2″ x 9 1/2″Pre-addressed EnvelopesSmall Flat Rate Envelope$7.75(commercial base)$8.95(Post Office)10″ x 6″Folded DocumentsChristmas cardsPassportsPadded Flat Rate Envelope$8.45(commercial base)$9.65(Post Office)12 1/2″ x 9 1/2″ClothingBooksVideo GamesDVDs and Blu RaysJewelryLegal Flat Rate Envelope$8.05(commercial base)$9.25(Post Office)15″ x 9 1/2″ResumesCertificatesTranscripts Did You Know? Businesses can save up to 33% on mail by using a postage meter Save money on your next postage meter by comparing free quotes get me a quote USPS Flat Rate Box Shipping PricesCurrent USPS Priority Mail Flat Rate box prices are as follows. (Be aware that Post Office pricing is the same as purchasing online):PackagingShipping PriceDimensionsIdeal for…Small Flat Rate Box$8.25(commercial base)$9.45(Post Office)Outside:8 11/16″ x 5 7/16″ x 1 3/4″Inside:8 5/8″ x 5 3/8″ x 1 5/8″BrochuresSmall ElectronicsMedium Flat Rate Box 1 (top-loading)$14.25(commercial base)$16.10(Post Office)Outside:11 1/4″ x 8 3/4″ x 6″Inside:11″ x 8 1/2″ x 5 1/2″Office SuppliesShoesMedium Flat Rate Box 2 (side-loading)$14.25(commercial base)$16.10(Post Office)Outside:14″ x 12″ x 3 1/2″Inside:13 5/8″ x 11 7/8″ x 3 3/8″Office SuppliesShoesLarge Flat Rate Box$19.20(commercial base)$21.50(Post Office)Outside:12 1/4″ x 12 1/4″ x 6″Inside:12″ x 12″ x 5 1/2″LaptopComputersGiftsAPO/FPO/DPO Flat Rate Box$17.70(commercial base)$20.00(Post Office)Outside:12 1/4″ x 12 1/4″ x 6″Inside:12″ x 12″ x 5 1/2″Sending Giftsto the troopsLarge Flat Rate Board Game Box$19.20(commercial base)$21.50(Post Office)Outside:24 1/16″ x 11 7/8″ x 3 1/8″Inside:23 11/16″ x 11 3/4″ x 3″Board GamesTips and TricksWeight LimitsThere’s a weight limit of 70lb for all packages shipped via USPS Flat Rate. To put that in perspective, here are some things that weigh about 70 lb:Ten laptopsNine gallons of waterOne office swivel chairFree packagingThe costs above apply to shipping with USPS. However, the actual Flat Rate boxes and envelopes are free. This means, if you so choose, you can order free packaging from USPS, then use it to ship your mail with a completely different delivery service. Bear in mind that boxes and envelopes ship within two to eight days of ordering.Next StepsIf your mail matches the required dimensions for USPS’s Flat Rate Priority Mail service, great. But if you want complete control over how your mail looks, you may prefer to ship using your own packaging, rather than the USPS-branded boxes and envelopes.If that’s the case, renting or leasing a postage meter is the way to go.Postage meters help you to weigh and calculate postage costs for all your packages without having to buy stamps from the Post Office. Your business will benefit from lower costs of metered postage as opposed to buying online or in branch.Expert Market can help you compare postage meter quotes. Simply fill out a short webform and we’ll put you in touch with top postage meter suppliers. Written by: Sabrina Dougall Web Marketing Expert Sabrina is a business journalist whose career began in news reporting. She has a master's in Investigative Journalism from City University London, and her work has appeared in The Times, The Daily Express, Money Saving Expert, Camden New Journal, Global Trade Review, and Computer Business Review. She specializes in writing about SEO (search engine optimization). Having run her own small business, Sabrina knows first-hand how critical digital marketing is to building a client base and local reputation. Reviewed by: Heleana Neil Business Services Editor Heleana Neil specialises in Business Services, managing the strategy and production of content for SMBs, helping businesses with the challenges and opportunities they face today. Covering everything from payroll to payment processing, Heleana uses her expertise to help business owners make better, informed decisions and grow their companies.