New Baby Congratulations Card: Sizes, Timing, and Messages

A new baby congratulations card is a folded card sent to parents within two weeks of a birth. The standard size is 5 x 7 inches. Write the baby's name, one or two sentences, and your signature. Mail it in an A7 envelope with one first-class stamp.

When to send

Send the card within 14 days of the birth. Parents receive many messages in the first month. A card that arrives in week one gets read. Cards that arrive after week six may get set aside.

For adoption, send the card when the placement is final or when the parents announce it. For a premature birth, wait until the parents share news. The CDC recorded 3,591,328 births in the US in 2023. That is about 9,840 per day.

Card size and paper

Most greeting cards use A2, A6, or A7 sizes.

Card stock weight ranges from 80 lb to 110 lb cover. That equals 216 gsm to 300 gsm. A 100 lb card stands upright. Thinner paper bends in the mail.

What to write

Keep the message short. Use the baby's name. Mention one detail the parents shared, such as the birth date or weight. Sign your full name.

Examples:

Avoid comments about sleep, weight, or future plans. Do not ask for a visit in the card. Do not include gift cards inside a card that may be opened in public.

Envelope and mailing

USPS First-Class Mail letters must measure at least 3.5 x 5 inches and at most 6.125 x 11.5 inches. Weight limit is 3.5 oz. The rate was 73 cents in 2024. Check the current rate at the post office.

An A7 card with envelope weighs about 0.5 oz. One first-class stamp covers it. Square envelopes cost extra. Write the return address on the back flap.

Card formats

Gift note

If you send a gift, place the card in the box or mail it on the same day. A card alone is enough. Parents keep cards. Many parents store cards in a memory box.

Read our complete guide: Wedding Invitation Cards: Styles, Wording, and Etiquette Explained