how many stamps do i need for a 7 oz envelope
Answers. Best Answer: go to www.usps.com, and click on Calculate Postage. I checked for 1st Class Mail for 6 ounces it's $2.02 (you will need five regular 42-cent stamps). For 7 ounces it's $2.19.You will need six stamps. For 8 ounces, it's $2.36. Six stamps will work here too. checked for 1st Class Mail for 6 ounces it's $2.02 (you will need five regular 42-cent stamps). For 7 ounces it's $2.19. You will need six stamps. For 8 ounces, it's $2.36. Six stamps will work here too.