Who jumps

Most units in this guide are posted around ages 2–14, with one adult attendant. A few listings differ. Birthday Bounce House prints 2–15. Read the spec block on the unit, then use judgment that is stricter than the printed band.

Toddlers and big kids

A four-year-old and a twelve-year-old are both “allowed” on a lot of these moonwalks. They should not share the floor. Bigger kids jump higher, land harder, and forget who is under them. Split the party into turns: little kids, then older kids, with a minute between so the small ones can get out the step without being launched.

If the party is truly for toddlers, look at the toddler inflatables on the booking site as well. A standard moonwalk can host them. It is a lot of vinyl for a two-year-old if older cousins are also invited.

How many at a time

For a typical 15-by-15 moonwalk, figure about 8–12 jumpers at a time. The 13-by-13 castles are closer to 8–10. Those are size-based guides on this site, not a headcount stamped as a hard cap on every item page. The giant boombox does not print a count here; ask when you reserve. When in doubt, fewer feet on the floor is the better party.

The adult watcher

One adult stays at the entrance the whole time the moonwalk is in use. Not a rotating teenager. Not a parent who steps inside to grab plates. The attendant watches the step, stops flips, and ends a turn when the mix of sizes goes wrong. That rule is the same on a character unit and on a plain castle.

Adults jumping with children is a common way a moonwalk gets overloaded. Grown-up weight changes the bounce for every smaller kid in the unit. If adults get in, the kid count drops hard, and it is still a judgment call you should clear with the crew. The safety note covers shoes, food, and the rest of the door rules.