Letter Mailing Cost: U.S. Postage by Weight, Size, and Destination

Key Takeaways

• Use the current standard domestic letter rate as a starting point, then account for weight and mailpiece classification.
• A Forever stamp covers the current standard one-ounce First-Class Mail letter rate, not every heavier or nonstandard envelope.
• Weigh the sealed envelope and measure its length, height, and thickness before using a postage calculator.
• Postcards, standard letters, and large envelopes, also called flats, have different postage categories.
• Retail, metered, and commercial postage suit different mailing volumes and preparation needs.
• Estimate a business mailing from the full job specification, including printing, inserts, postage, and any added services.

Start with the standard domestic letter rate

For a standard-sized, rectangular domestic letter, use the current standard one-ounce First-Class Mail rate as your starting point. United States Postal Service lists standard-sized, rectangular letter stamps starting at $0.82; postage can be higher when weight or format changes the mailpiece’s classification.

A Forever stamp remains valid for the current standard one-ounce First-Class Mail letter rate when prices rise. It does not automatically cover a heavier letter or one that falls into a nonstandard category, so calculate postage for the complete piece instead of assuming one stamp is enough.

When using stamps with printed denominations, add their values to reach the postage required. For older stamps without a clearly printed value, verify their current postage value before using them toward today’s standard letter rate.

Standard rectangular letters start at $0.82; square, oversized, or unusual envelopes start at $1.31.

Source: United States Postal Service

Rates change over time, so a number copied from an old mailing or rate chart may no longer apply. Use current postage information for the date you plan to mail.

Weigh the complete letter before calculating postage

Weigh the sealed, ready-to-mail envelope, not just the letter pages. The paper, inserts, envelope, and every enclosure contribute to the mailpiece’s total weight.

A small digital scale that measures in ounces or grams can help you weigh a home mailing. Place the complete sealed envelope on the scale, record its weight, and enter that measurement, the mailpiece type, and the destination into a current postage calculator.

Calculator results depend on accurate inputs. If you weigh only the letter pages or enter the wrong mailpiece category, the postage estimate may not match the finished envelope.

When a letter weighs more than the amount covered by its base postage, additional postage is required. Use the current rate schedule to find the amount for the complete weight instead of assuming one stamp covers every letter.

For a small stack of identical letters, weigh a finished sample that includes all inserts and the envelope. If the contents or paper change, weigh a new sample before calculating the postage for the full mailing.

Measure the envelope and check its shape

Measure the envelope’s longest side for length, then measure the side at a right angle for height. Check thickness at the mailpiece’s thickest point, and enter all three measurements when using a postage calculator.

Square, oversized, rigid, lumpy, or unusually shaped envelopes can require more postage or be classified as nonmachinable. United States Postal Service lists letter stamps for square, oversized, or unusual envelopes starting at $1.31.

Keep postcards, standard letters, and large envelopes distinct when estimating postage. A large envelope, also called a flat, uses a different mailpiece category from a standard letter, so do not apply a letter rate to it just because it contains a folded sheet of paper.

Shape and thickness matter as much as the outer dimensions. A stiff insert, uneven enclosure, or raised decoration can keep an envelope from moving through standard letter processing, so consider the completed piece rather than measuring an empty envelope.

Compare retail, metered, and commercial postage

Single-piece retail postage suits individual letters and small mailings. You can apply stamps or use a retail postage option, then send each prepared envelope through the mail.

Metered mail uses approved postage equipment or software to print postage on a mailpiece or label. It can make repeat business mailings easier to process when your team regularly prepares letters in-house.

Commercial postage and presort options can suit larger, organized mailings. These approaches typically require mail preparation, such as sorting pieces by destination, and meeting applicable volume or eligibility requirements.

Before choosing an approach, compare postage-only costs with the work your team must complete. If the letters are already printed, addressed, and inserted, postage may be the main remaining task; if not, printing and mailing service can combine more of the job.

For print orders that need postage added separately, Additional postage covers postage costs and is configured in addition to products that do not include postage. It costs $0.82, making this a relevant option to compare when budgeting for a print order that needs postage added.

Commercial or presorted postage is not simply a different stamp choice. It involves organizing the mailing to meet applicable requirements, so compare the preparation work alongside the postage rate when deciding whether it suits your campaign.

Choose the right mailing option for the job

International letter postage depends on destination, weight, and format. Enter the destination country and complete mailpiece measurements in a current postage calculator, and consider a Global Forever stamp where it applies.

International delivery time varies by destination and mailing conditions. If the letter has a time-sensitive purpose, allow for transit variability and choose an appropriate service based on the delivery needs rather than treating ordinary letter postage as a guaranteed arrival date.

Basic letter mail does not provide the same documentation as services such as Certified Mail. When tracking, delivery evidence, or a signature matters, choose an added service that provides the level of documentation your mailing requires and include its charge in your estimate.

Use regular letter mail for straightforward correspondence. For a legal, administrative, or business matter that requires a record of mailing or delivery, consider an option with additional documentation and retain the mailing records with your files.

Budget for business letters and mailing changes

Build a campaign estimate from the complete mailpiece specification, not from stamp cost alone. Include quantity, paper and inserts, envelope dimensions, weight, postage class, and any added services.

Postage rates change over time, so an old rate table may lead to an inaccurate budget for a new campaign. Recalculate with current weight, measurements, destination details, and the planned mailing method.

When you compare a postage-only option with a service that prints, prepares, and mails letters, identify which production steps each option covers. The Already mail merged letters & mailing service is for customers who upload their merged letter and envelope PDFs; it prints, inserts, seals, stamps, and mails them using regular First-Class postage. Its price is $54.03.

This service suits a team that has already prepared the merged documents and wants the printing and mailing steps handled. Compare its $54.03 price and included work with postage-only costs to see which production tasks would otherwise stay with your team.

A larger mailing gives you more responses to evaluate, but the outcome still depends on factors such as your audience, offer, design, timing, and follow-up.

We work to meet each individual request with careful consideration of what is reasonable and cost-effective. To compare the available production steps for a business mailing, explore our letter printing and mailing services.

Frequently Asked Questions