how much postage for a small card?
Letter size requirements for $0.47 postage rate:*. Post card size requirements for $0.34 postage rate: Large envelope size requirements for $0.94 postage rate: NOTE: If one of the above dimensions for the minimum envelope (6 1/8â³ x 11 1/2 x 1/4) are exceeded, the envelope will be considered a large envelope.