The bar mitzvah ceremony for boys or bat mitzvah for girls when they turn 13 -- although some Jewish girls celebrate a bat mitzvah at 12 -- is a coming-of-age ceremony that formally marks the age when Jewish children become responsible for observing the commandments. Guests at a bar mitzvah party typically bring gifts, such as cash, to celebrate the milestone. Although no guidelines exist on the set amount you should give for a bar mitzvah, being familiar with Jewish customs can help you determine an appropriate gift.
Multiples of 18
Cash gifts for bar mitzvahs are typically given in multiples of 18, such as $18, $36 or $54. Eighteen is the numerical value of the hay and yud, which make up the word "chai," Hebrew for "life." Gifts in increments of 18 -- a long-held tradition -- express your hope that the recipient enjoys a long and prosperous life, according to Chabad.org. However, you won't find a specific increment of $18 that is required or customary.
Amount to Give
Consider your relationship with the recipient and your resources when you're deciding how much to give. For example, you'll likely want to give a larger gift to a close family member than to a school acquaintance of your son or daughter. You can also consider how much you'd give the person as a birthday gift; a bar mitzvah is more special than a birthday, but that amount can serve as a baseline estimate. "The Everything Etiquette Book" recommends using $50 as a starting point or $100 for close friends and family. Average gift amounts vary widely by community, however, so check with a friend or the rabbi if you're still uncertain.
Alternatives to Cash
You don't have to give cash for a bar mitzvah; you can alternately give Jewish-themed gifts, such as biographies of Jewish people or a Jewish prayer book, or other presents related to the recipient's hobbies or interest. However, remember that a bar mitzvah is a spiritual event, not just a birthday party, so try to give a gift with meaning, such as planting trees in Israel, which are available in increments of -- what else -- $18 per tree.
Considerations
Bar mitzvah gifts are typically given at the party rather than at the service, since in most cases, not everyone attending the service will go to the party -- if there is one. However, some branches of Judaism, such as Orthodox Judaism, prohibit carrying gifts in the Synagogue or at all during Shabbat. If the bar mitzvah occurs on Shabbat -- Friday night or Saturday before sundown -- you may want to send your gift before or after that day. If you aren't sure what to do, ask the child's parents or a rabbi for guidance.