88 Cents or Two Stamps

• A standard manila envelope weighing 1 oz. or less requires 88 cents of postage, according to the Internet Accuracy Project. As of 2010, a first-class stamp costs 44 cents, so two stamps equal 88 cents.
  
  

Heavier Envelopes Cost More

• Manila envelopes weighing more than 1 oz. will cost more than 88 cents. In addition, manila envelopes that are larger than the standard size will be more expensive to mail.
  
  

Bottom Line

• A manila envelope weighing an ounce or less can be mailed with two first-class stamps, as of August 2010, but larger or heavier envelopes may cost more. Take your manila envelope inside a post office to calculate its exact cost.