Of all the questions we get asked, this is the most common by far. It sounds like it needs a complicated formula, but it really doesn't — sizing a silent disco comes down to two things: who's genuinely going to dance and how much buffer you'd like.
The short version
One headphone per dancing guest, plus around 10% extra. That buffer covers three things: guests arriving late, a pair needing a charge or swap mid-party, and the odd guest handing their headphone to a friend for a song.
Below, we break this down by event type, because "dancing guest" means something different at a wedding, a kids' party and a school disco.
Weddings — count evening guests only
Ceremony and daytime guests won't need headphones. It's the evening reception crowd that fills the dancefloor, so that's the figure to work from. Your invitation numbers should give you a good starting point.
- Up to 25 evening guests → our 25-headphone package.
- 26–50 evening guests → the 50-headphone package.
- 51–100 evening guests → the 100-headphone package.
- 100+ evening guests → combine packages — get in touch.
Even guests who don't intend to dance often want to try a pair out of curiosity, which is exactly why that 10% buffer matters. If your evening list is around 55, go for the 100-pack rather than stretching the 50-pack — being short on headphones is the one thing couples occasionally mention afterwards.
On the fence between two package sizes? Always round up. A handful of spare headphones at the end of the night beats telling a guest they'll have to wait for one to free up.
Kids' parties — one per child, plus spares
Children share, drop, wander off with, and occasionally sit on their headphones. Add 2–3 spare pairs on top of the headcount.
- Up to about 22 children → the 25-pack.
- 23–47 children → the 50-pack (great for joint birthdays).
- Big class or year-group parties → the 100-pack.
Helping parents usually don't need their own pair — but a couple of spare adult-sized ones let them join in the fun, which kids always enjoy.
General parties — plan for the peak, not the invite list
At 40th birthdays, anniversaries and garden parties, it's rare for absolutely everyone to be dancing at once. Typically 70–80% of guests will be on the dancefloor at any given moment — the rest will be in the kitchen, outside for some air, or watching from a chair.
Take your total guest number, multiply by 0.8, and use that figure. A 60-person birthday party is usually well served by the 50-pack.
Schools & colleges — size for the room, not the register
A frequent mistake is assuming a whole-school disco needs a pair for every pupil. In reality, you're capped by how many students are in the hall at any one time, and how the sessions are staggered across year groups. Size for the largest single session.
- Single class (Year 6 leavers, sixth form social) → 50-pack.
- Whole key stage rotation (KS2 in one session) → 100-pack.
- Prom or full year assembly → 100- or 150-pack.
We can turn the kit around between sessions if you're running KS1 in the morning and KS2 in the afternoon — just let us know at enquiry stage and we'll note it on your booking.
Proms — one per ticket
Prom is a different case from a normal school disco: attendance is confirmed by ticket sales, and nearly everyone dances at some stage of the evening. Size for one headphone per ticket sold, and confirm final numbers with us a week before.
What if you get the number wrong?
Let us know as soon as you can. Adding a small top-up pack to your existing booking is usually possible if we have stock free — and we'll always try. The earlier you flag it, the better chance we have of sorting it.
Ready to size up your event? Check availability and we'll suggest the right pack in our reply.