1. What Is USPS Weight Per Stamp?

The USPS (United States Postal Service) standard weight per stamp is 1 ounce for First-Class Mail. This means one Forever stamp covers the cost to mail a 1-ounce letter. For heavier items, additional stamps are required.

2. How Does The Calculator Work?

The calculator uses the simple formula:

Where:

• Package Weight — Weight of your mail item in ounces
• 1 oz — Standard weight covered by one Forever stamp
• ceil() — Round up to the nearest whole number

Explanation: Since USPS requires full stamp coverage for each additional ounce or fraction thereof, we always round up to ensure proper postage.

3. Importance Of Correct Stamp Calculation

Details: Proper stamp calculation ensures your mail is delivered without delays or return due to insufficient postage. Underpaying may result in mail being returned to sender or additional postage fees for the recipient.

4. Using The Calculator

Tips: Enter your package weight in ounces. Use a precise scale for accurate measurement. Remember that envelopes and packaging materials add weight to your mail item.

5. Frequently Asked Questions (FAQ)

Q1: What if my mail weighs more than 1 ounce?
A: Each additional ounce requires additional postage. For 2 ounces, you need 2 stamps; for 1.1 ounces, you still need 2 stamps.

Q2: Are Forever stamps always sufficient?
A: Forever stamps cover the current First-Class Mail rate for 1 ounce. They remain valid even if postal rates increase.

Q3: What about international mail?
A: International rates are different and typically higher. This calculator is for domestic USPS First-Class Mail only.

Q4: Do large envelopes require more postage?
A: Yes, large envelopes (flats) have different pricing. This calculator is for standard letter-size mail.

Q5: What if I need to mail something very heavy?
A: For packages over 3.5 ounces, consider USPS Priority Mail or other shipping services which may be more cost-effective.