Wedding Invitation Postage 2026: How Many Stamps You Need (With Examples)
Quick answer: how many stamps and what it costs
- Most common (1 oz, standard rectangular, machinable): 1× Forever stamp — $0.78. Covers many simple 5×7 invitation postage setups when the finished piece is at or under one ounce and meets letter rules. See how many stamps for 1 oz.
- Slightly heavier suite (2 oz, still machinable): postage is $1.07 — often one 2 oz wedding-style stamp or an equivalent stamp mix, not “two random Forever stamps.” Details: 2 oz postage.
- Square, rigid, or lumpy (often non-machinable): add $0.49 on top of the correct postage for weight — e.g. many square wedding invitation postage scenarios. Wax seals and bulky closures often route here too. Read: non-machinable mail.
This page is built for couples asking wedding invitation postage 2026, how many stamps for wedding invitations, and wedding invitation postage cost with real examples—not generic advice. Use the quick answer above, then match your suite to one of three cases below.
Wedding Stamp Calculator — use the calculator to get your exact postage from weight, ounces, and surcharges.
Most people fall into these 3 cases
Your wedding invitation weight and postage almost always land in one of these. Stamps needed = enough total cents for the class and weight (not always “one stamp”).
Case 1: Standard lightweight invite (~1 oz)
- Stamps / postage: typically $0.78 — 1× Forever for a standard machinable letter.
- When it applies: thin cardstock, few inserts, rectangular envelope, flexible, passes automated processing rules.
- Anchor check: 1 oz stamp requirements.
Case 2: Heavier suite (~2 oz)
- Stamps / postage: $1.07 for a machinable First-Class letter at two ounces (e.g. dedicated 2 oz wedding stamps or exact combinations).
- When it applies: thick cardstock, multiple inserts, reply card + envelope inside, liners — typical “full” suites.
- Anchor check: 2 oz stamp requirements.
Case 3: Square, wax seal, or non-machinable handling
- Stamps / postage: correct letter rate for actual weight plus +$0.49 non-machinable surcharge when USPS classifies the piece that way (common for square envelopes and some rigid/lumpy designs).
- When it applies: square flap, heavy wax on the outside, uneven thickness, or other traits that take the piece out of normal automation.
- Anchor check: Square envelope postage · Non-machinable surcharge explained.
Scenario table: invitation type → stamps → cost
Use this as a decision aid. Your real suite might differ — weigh one finished sample. For stamps for 5×7 wedding invitations, size alone does not set postage; weight and shape do (see 5×7 envelope postage).
| Invitation type | Weight (typical) | Shape / notes | Postage due | Cost (domestic) |
|---|---|---|---|---|
| Minimal 5×7 + single insert | ~1 oz | Rectangular, flexible | 1 oz letter | $0.78 |
| 5×7 + RSVP card & reply envelope | often ~2 oz | Rectangular, flexible | 2 oz letter | $1.07 |
| Thick cardstock + multiple inserts | often ~2 oz+ | Rectangular | 2 oz (or more if over 2 oz) | $1.07 + additional ounces if needed |
| Square envelope suite | 1–2 oz typical | Square → often square wedding invitation postage + surcharge | Letter rate for weight + NM | e.g. $1.27 (1 oz + $0.49) or $1.56 (2 oz + $0.49) |
| Wax seal / bulky closure | varies | May be non-machinable | Letter rate + NM if applicable | Base + $0.49 when surcharge applies |
Wedding Stamp Calculator — use the calculator to get your exact postage from weight, ounces, and surcharges.
Dedicated tool with preset wording: Postage calculator for wedding invitations.
2026 rate chart (reference)
Same numbers as the rest of the site; use as a reference while planning wedding invitation postage cost. International mail uses separate pricing.
| Weight / type | Requirement | Total cost |
|---|---|---|
| 1 oz | Machinable letter (standard rectangular, flexible) | $0.78 (1× Forever) |
| 2 oz | Machinable letter | $1.07 (e.g. 2 oz wedding stamps) |
| +1 oz | Each additional ounce after the first | +$0.29 per oz |
| Postcard | USPS-eligible postcard (size rules apply) | $0.61 |
| Non-machinable | Surcharge when square, rigid, lumpy, or otherwise non-machinable | +$0.49 on top of correct letter postage |
| International letter | From U.S. (confirm class at mailing) | $1.70 |
What counts as a “standard” invitation?
In USPS terms, “standard” usually means a machinable First-Class letter: within letter size limits, rectangular (aspect ratio rules), flexible enough for processing, and not lumpy or rigid in a way that blocks automation. A plain 5×7 in a baronial or A7 envelope can still be 1 oz or 2 oz — what matters is total weight and whether the piece is non-machinable. That is why wedding invitation weight and postage should be measured on a finished sample.
What makes an envelope non-machinable?
Non-machinable is not a vibe — it is a handling category. Square envelopes often qualify because automation is built around rectangular mail. Wax seals, thick charms, or uneven thickness can also push a piece into manual handling. When the $0.49 surcharge applies, it stacks on the correct postage for weight. Full detail: non-machinable mail guide.
Why wedding invitations often cost more to mail
A utility bill in a standard envelope is not the same as a wedding suite. Invitations are meant to feel special — which usually means more weight and bulk than “one Forever stamp and done.”
Cardstock and layers
Wedding paper is often thicker than office stock. Cotton or double-ply paper, pocket folds, and backing layers add fractions of an ounce that stack quickly.
Inserts and details
RSVP cards, details cards, maps, and registry inserts add sheets and cards — each piece counts toward total weight.
Liners and embellishments
Envelope liners add weight and sometimes thickness. Ribbons, belly bands, and tied closures can change flexibility and how the piece moves through sorting equipment.
The “one stamp” myth
A single $0.78 Forever stamp covers one ounce for a standard machinable letter when size and shape rules are met. Cross into two ounces or non-machinable territory and the math changes — that is normal First-Class pricing, not a mistake.
Before you order hundreds of stamps, run your numbers with our Stamp Calculator so you see whether you are in the $0.78, $1.07, or surcharge range.
The hidden costs of square envelopes and wax seals
Beautiful design choices often overlap with postage that costs more — because automation cannot reliably process certain pieces.
Square envelopes
Square envelopes often trigger the non-machinable path: the $0.49 surcharge on top of the correct postage for weight. That is separate from whether you are at one ounce or two. Many square suites are correct letter postage for weight + $0.49 when the surcharge applies.
Wax seals and bulky closures
Wax seals, metal charms, thick twine, or lumpy bows can make an envelope rigid or uneven — another path to non-machinable handling. Outer seals that change thickness are a common risk.
If you love wax, ask your stationer about inner envelopes, seal placement that keeps the outer face flatter, or finishes that preserve a smooth, flexible mail surface.
Weight is not the only input
Even when your kitchen scale says one ounce, shape, flexibility, and uniformity still matter for pricing and processing. That is why the Post Office stress test below matters.
Examples of invitation suites (what drives weight)
Same layout as your design proof, fully assembled: outer envelope, liner, invitation, RSVP set, inserts. A details card plus RSVP reply plus reply envelope is normal — and a big reason many suites land near two ounces. Remember: $0.29 applies per additional ounce after the first. $1.07 2 oz stamps match many standard rectangular two-ounce suites when no non-machinable surcharge applies. If +$0.49 applies, build it into the budget before you commit to a square format.
Common mistakes (and how to avoid them)
- Assuming one stamp is always enough. Many suites are 2 oz or need a surcharge — buy to the actual cents due, not “one Forever per envelope.”
- Forgetting RSVP postage. Guests usually should not pay to mail the reply — include reply postage in your stamp budget (postcard rate or 1 oz letter, depending on your reply format).
- Ignoring square / non-machinable surcharge. Square wedding invitation postage often adds $0.49 on top of weight-based postage.
- Not weighing a finished invitation. Kitchen scales help, but a counter weigh-in confirms class and surcharges.
- Mixing up “two Forever stamps” with 2 oz postage. Two Forevers at $0.78 = $1.56 — more than the $1.07 due for a standard 2 oz machinable letter.
Wedding Stamp Calculator — use the calculator to get your exact postage from weight, ounces, and surcharges.
How much will it cost total?
Below is outbound postage per invitation envelope (what you put on the outer envelope guests receive). RSVP reply postage is extra — plan stamps for each reply piece you include (often comparable to one postcard or one 1 oz letter per household).
| Scenario (outer envelope only) | Cost per invite | × 50 | × 100 | × 150 |
|---|---|---|---|---|
| 1 oz machinable | $0.78 | $39.00 | $78.00 | $117.00 |
| 2 oz machinable | $1.07 | $53.50 | $107.00 | $160.50 |
| 1 oz + non-machinable surcharge | $1.27 | $63.50 | $127.00 | $190.50 |
| 2 oz + non-machinable surcharge | $1.56 | $78.00 | $156.00 | $234.00 |
Example: How much does it cost to mail 100 invitations? If your suite is 2 oz machinable, outer postage is about $107 for 100 envelopes — plus RSVP stamps and any international guests (2 oz breakdown).
Pro-tip: Post Office stress test
The fastest way to calm “insufficient postage” anxiety is to stop guessing and get an official read on a finished piece.
Checklist
- Assemble one invitation exactly as guests will receive it— same paper, inserts, liner, ribbon, and seal.
- Bring that sample to the Post Office counter and ask staff to weigh it and confirm class and surcharges.
- Ask: Is this machinable or non-machinable? Will square or wax affect processing?
- If you have multiple versions (international vs. domestic, different inserts), repeat for each version.
- Save the exact stamp configuration you will replicate — especially if you combine stamps to reach $1.07, $1.70, or base + $0.49.
After you have real numbers, double-check with our Stamp Calculator.
International guests
If part of your list is outside the United States, do not assume domestic stamps apply. Plan for the $1.70 international letter rate from the U.S. for a typical letter, and confirm the exact classification at the counter or with current USPS materials when you mail.
FAQ
How many stamps for a 5×7 wedding invitation?
Depends on finished weight and shape — not the 5×7 card size alone. Many all-in-one suites are 1 oz ($0.78) or 2 oz ($1.07). If the envelope is square or non-machinable, add $0.49. See 5×7 envelope postage.
Do wedding invitations need extra postage?
Often yes, compared to a single bill in a #10 envelope. Extra can mean second ounce ($1.07 total for many suites) or non-machinable surcharge (+$0.49) for square or bulky design — plus separate postage for RSVP replies.
What makes an envelope non-machinable?
Common triggers include square shape, stiffness, uneven thickness, and certain closures — anything that keeps the piece from running cleanly through automated sorting. USPS applies a $0.49 surcharge when that handling applies, on top of correct weight-based postage.
How much does it cost to mail 100 invitations?
For the outer envelope only, a typical 2 oz machinable suite is about $107 in postage at $1.07 each. A 1 oz suite would be about $78. Add RSVP stamps and any surcharges or international pieces separately.
Can I use two Forever stamps instead of one 2 oz stamp?
Yes, but you usually overpay. Two Forever stamps at $0.78 each equal $1.56, while correct 2 oz postage for a standard machinable letter is $1.07. Overpaying is allowed, but it is rarely the best use of budget.
Does the RSVP envelope need a stamp?
Yes — etiquette expects the couple to provide it. Guests should mail the RSVP without paying postage. Include RSVP stamps in your plan and verify weight if you add extras.
How many stamps for a square invitation?
You need postage for the correct First-Class letter cost for actual weight, plus the $0.49 non-machinable surcharge when square (or otherwise non-machinable) handling applies. The count of physical stamps depends on denominations you buy — focus on total postage required, not “one Forever and hope.”
Will 2025 stamps still work in 2026?
Yes. Forever stamps remain valid for the service they cover; they do not expire because you bought them in a prior year. Always ensure the piece still meets current size, shape, and thickness rules.
Get an estimate for your suite
Not sure how much your specific suite weighs? Use our Wedding Stamp Calculator for an instant estimate — then confirm with a Post Office weigh-in on a physical sample before you commit to hundreds of stamps.