All About Business-Sized #10 Envelopes

Young businesswoman licking envelope seal at desk

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If you're not familiar with what #10 envelopes are, you might know them better as business-sized or standard envelopes. Even if you don't know their name, you'd probably recognize their long, thin shape, and you've surely received them in the mail.

If you enter sweepstakes, you probably know that some giveaways require them for entry. So here's an overview of these popular envelopes including what exactly they are and how you can get them inexpensively — or even make them yourself!

What Is a #10 Envelope?

#10 envelopes have a standard size of 4 1/8 inches high by 9 1/2 inches long. They're designed to hold a standard 8 1/2 x 11-inch piece of paper folded into three sections, making them practical for office use. They're perfect for sending invoices, checks, official correspondence, and other business letters

#10 envelopes and letter-sized envelopes are the most commonly used in America. Letter-sized envelopes are commonly used for informal letters; many stationary sets come with this size envelope. Compared to #10 envelopes, letter-sized envelopes are narrower but broader and closer to square-shaped.

Where to Find #10 Envelopes

If you're in the United States, #10 envelopes are easy to find. You can buy them directly from the post office, from office supply stores like Staples or Office Depot, from online stores like Amazon, and you can usually find them at any big-box store or major retailer that sells stationary or school supplies.

How to Make Your Own #10 Envelopes:

Need a #10 envelope in a hurry, and don't want to run out to the store? Or maybe you'd like to save money by turning a regular piece of paper into the envelope you need? As it turns out, you can easily create your own #10 envelope with nothing but a glue stick, a ruler, some scissors, your printer, and this envelope folding tutorial from Instructables.

It might take a little practice to get these steps right, but if you need an envelope in a pinch, being able to simply make one yourself comes in handy!

Using #10 Envelopes to Enter Sweepstakes:

If you want to enter mail-in sweepstakes, #10 envelopes are one of the essential supplies you'll need to have on hand. Many sweepstakes specify in their rules that only a standard business-sized envelope will do to enter.

Be sure to follow the rules carefully, because using the wrong-sized envelope could disqualify you from the sweepstakes and destroy your chances of winning. Many sweepstakes sponsors will disqualify anyone who deviates from their rules, even for something as seemingly unimportant as the envelope their entry arrives in.

How to Save Money While Buying #10 Envelopes

Many places sell #10 envelopes, which means that there are plenty of chances to comparison shop for a good deal. Here are some of the places to check to see where you can get the best prices when you're buying business-sized envelopes:

  • Specialist online shops like
  • Large online retailers like Amazon
  • Big box retailers like Walmart or KMart
  • Office supply stores like Staples or Office Depot
  • Grocery and drug stores
  • Warehouse stores like Sams Club or Costco
  • Special deals on eBay

Comparison shop among these options to find out which has the best deals in your area.

With some luck, you can also find #10s on sale at thrift stores, yard sales, and flea markets which usually offer deep discounts. By shopping around these locations, you can save money buying #10s.

Don't forget to use coupons and gift cards to reduce your envelope costs even more, when you have the opportunity.