Wedding invitation postage calculator
Invitation suites are heavier than people expect — inner envelopes, RSVP cards, liners, wax seals. Price the full run before you buy stamps: per invitation, RSVP return postage included, times your guest list.
What an invitation suite actually weighs
| Piece | Typical weight |
|---|---|
| Invitation card | 10–15 g |
| Outer envelope | 8–12 g |
| RSVP card + return envelope | 10–14 g |
| Details card / map | 5–8 g |
| Envelope liner, tissue, belly band | 4–8 g |
| Wax seal | +2 g — and the bump can force oversize pricing |
A typical assembled suite lands between 40 and 70 g — over the 50 g line where a standard envelope jumps to oversize pricing ($2.61 within Canada). Three rules keep this cheap: weigh one fully assembled invitation before buying any stamps (a kitchen scale is fine); buy stamps after weighing, not when the invitations arrive; and if you're near a boundary, dropping one insert or a lighter liner can save more than a dollar per guest across the whole run. Square invitations and anything over 5 mm thick price as oversize regardless of weight — the calculator's checkbox accounts for it.
Mailing a test invitation to yourself is the oldest trick in wedding planning for a reason: it proves the weight, the postage, and that the suite survives the sorting machines. For the stamps themselves, the combination finder can build exact postage from stamps you already own.