Recently, my younger son celebrated his first birthday. We had a quiet party for him at home, inviting family friends to share brunch and a homemade cake. This was in sharp contrast to his older brother’s first party, held at an aquatic center with a gaggle of kids. Afterward, I asked myself, which party was better? Is there an optimal number of guests for a toddler’s party?

In some families, conventional wisdom suggests that you should invite the same number of children as your child’s age. In other words, when your child turns one, you have one young guest at the party. But does anyone actually follow this advice? My informal poll netted a wide range of answers.

"That’s a stupid rule," declared my best friend Sara Richardson, mother of one. "I had 30 people at my daughter’s first birthday party."

"I’ve never heard of that rule," said Kellie Kelly, of Ijamsville, Md., mother of two. "Mostly we’ve just invited family. All of our parties have been at the house. We invite the kids she plays with on a day-to-day basis."

Jodi Howard is a Washington, D.C., mom planning her son’s first birthday gathering. "I have heard of the number of kids rule, and I don’t think it is a bad idea once the child is aware of numbers. It helps keep things under control and cuts back on hurt feelings. If you don’t have that rule, I feel you need to invite the entire class and that can get expensive and ridiculous."

Karen Bush, mother of three, living in Great Falls, has followed the number of kids rule for years. "The rule has worked well for us, and we’ll continue to use it as long as it makes sense. Once my older daughter hits middle school, we’ll probably go for smaller gatherings."

Limiting the number of children at your child’s birthday party has some obvious advantages. As Bush points out, "The pros of this rule are that it’s true: Young children really don’t have attention spans to include a lot of kids, it makes for an easier tribe of kids to handle, and the kids report they enjoy having a smaller get-together with fewer toys and thank-you notes to write."

But there are disadvantages, too. Paring down your guest list may be impractical. As Kelly noted, her 4-year-old daughter was once in a playgroup with three sets of twins. Whether in a playgroup or at school, if your child is invited to a party and doesn’t reciprocate, there may be hard feelings.

In some families, you may be breaking with tradition if you choose to have a small party for your child. For example, the Tongan custom is to celebrate a child’s first birthday with a luau, complete with food, music, flowers and dancing. Other cultures also hold a child’s first birthday in high regard.

"The first and fifteenth birthdays are the most important in Latin American cultures," said Roxana Dubin, a mother of three who lives in Gaithersburg. She said that she hasn't celebrated large first birthday parties in the United States, noting that her relatives primarily live in Peru. Roxana adds, "You would love to follow your traditions, but economically, it is hard to do so."

A carefully selected guest list can ensure that you don’t spend more than you intended for your child’s next party. As you prepare the invitations, keep these questions in mind:

• Would my child prefer a large number of guests or an intimate group? Your answers may differ for your laid-back son and your up-for-anything daughter.

• Who is likely to be offended if they are taken off the guest list? Anticipating hurt feelings is the first step toward preventing them. If you can’t invite your son’s entire preschool class to his birthday party, you might take a special snack or party favors to school.

• What is the expected cost per child of the planned activity? If you are having a picnic at the park, adding a few extra children won’t make much difference financially. But the costs can add up if you include those same guests in a structured activity, like going to an amusement park.

• Are your proposed guests likely to get along? In What to Expect the Toddler Years, the authors Arlene Eisenberg, Heidi E. Murkoff and Sandee E. Hathaway note that at the age of two, "The commonly accepted practice of ‘one guest for every year’ may add up to one guest too many at this age." They recommend having an even number of children at the party so that the kids can play in pairs.

Whether you decide to have a small party or a large bash, bear in mind that what you think is crucial to a successful party may not matter to your child. I asked my 4-year-old son what makes for a good birthday party, expecting him to comment on special activities or time spent with friends. "The best thing about birthday parties," he replied enthusiastically, "is eating the cake!"