There is no single physical size for every U.S. postage stamp; commemorative, definitive, coil, booklet, and service stamps use different formats.
Why dimensions vary
Artwork, sheet layout, printing format, and service category all affect physical size. Coils and booklets may use different perforations or die cuts from panes.
Placement matters more than size
Affix valid postage flat in the upper-right corner of the address side. Do not overlap stamps, cut them, or cover them with tape.
Stamp size versus envelope size
The dimensions of the envelope—not the stamp—help determine whether the mailpiece qualifies as a postcard, letter, large envelope, or package.
Frequently asked questions
How big is a postage stamp?
Sizes vary; many common stamps are around one inch across, but there is no universal dimension.
Does a larger stamp have more value?
No. Value comes from the printed denomination or category.
Can I trim a stamp?
Do not cut or alter postage stamps.
Sources and update note
- USPS Notice 123 — current price list
- USPS DMM 101 — physical standards
- USPS DMM 604 — postage payment methods
Rates and mailing standards can change. This page was reviewed in August 2026; verify the completed mailpiece when its weight, dimensions, shape, destination, or services are uncertain.
Measured issue examples—not one universal stamp size
“Stamp size” can mean the printed design, die-cut shape, perforated single, booklet pane or the mailpiece area available for postage. USPS product specifications vary by issue. Examples checked in official issue material include:
- Love 2025: 0.9100 × 1.1900 inches.
- Bruce Lee: 1.5600 × 0.9800 inches.
- Goodnight Moon: 1.5600 × 1.2250 inches.
Use the issue-specific specification when designing an album mount or envelope layout. Mailpiece dimensions are a different ruleset, and this page concerns postage—not rubber-stamp dimensions.