How many stamps needed for a large envelope * **Lightweight (up to 1 oz or 28 grams):** In the United States, for example, a single First-Class Mail Forever stamp is sufficient for letters up to 1 oz. If your large envelope weighs more than 1 oz but less than 2 oz, you will need to add an additional ounce stamp. For each additional ounce, you will need another ounce stamp. * **Heavyweight (over 1 oz):** For heavyweight large envelopes, you will need to use Priority Mail Flat Rate Envelopes. These envelopes come with a specific amount of postage pre-paid, based on the envelope size, not the weight. You can purchase these envelopes online or at the post office. 2. **International Letters (outside the same country):** The number of stamps needed for a large envelope depends on several factors, including the weight of the envelope, the distance it is being sent, and any additional services required. Here is a general guide to help you determine how many stamps you need for a large envelope: 1. **Domestic Letters (within the same country):** * **Lightweight (up to 1 oz or 28 grams):** In the United States, for example, a single First-Class Mail Forever stamp is sufficient for letters up to 1 oz. If your large envelope weighs more than 1 oz but less than 2 oz, you will need to add an additional ounce stamp. For each additional ounce, you will need another ounce stamp. * **Heavyweight (over 1 oz):** For heavyweight large envelopes, you will need to use Priority Mail Flat Rate Envelopes. These envelopes come with a specific amount of postage pre-paid, based on the envelope size, not the weight. You can purchase these envelopes online or at the post office. * **Certified Mail:** If you require a return receipt or proof of delivery, you will need to use Certified Mail. This service typically adds an additional fee of around $3.50 to your postage. * **Registered Mail:** If you need to send valuable items, you can use Registered Mail. This service provides insurance and tracking for your mailpiece. The cost depends on the value of the items being sent. * **Insurance:** If you need to insure your large envelope, you can purchase additional insurance at the post office. The cost depends on the value of the items being sent.