How many wireless headphones do I need?

One headphone per person, plus roughly 10% spares. For 50 people, order 55. For 100, order 110. That covers the person who turns up unannounced, the one who sits on a headphone, and the one that comes back flat because nobody plugged it in overnight.

That’s the short answer and it’s right most of the time. Below are the situations where it isn’t.

When you need fewer than one each

Seated presentations and screenings. If people are seated and the audience is fixed — a conference room, an outdoor cinema with ticketed seats — you can order to the seat count rather than the guest count. Nobody is wandering in.

Rotating groups. School incursions and museum tours often run the same session four times a day with a different group each time. You need enough for the largest single group, not the total across the day. A school running four classes of 28 needs 30 headphones, not 112.

That distinction alone has saved people the cost of a second kit.

When you need more than one each

Open events with no guest list. Street parties, festival activations, anything where the crowd is whoever turns up. Order to your realistic peak, not your average, and add 15% rather than 10%.

Multi-day hires without overnight charging. Headphones run around 8 hours per charge. If you’re running a two-day event and can’t charge overnight, you need a second set for day two — or, far cheaper, ask for the charging unit and plug them in. Chargers are included at no extra cost, so this is almost never worth solving with more headphones.

Anything involving kids under about ten. Not because they break them, but because the size adjustment gets fiddly and it’s useful to have a couple already set and ready to swap.

Transmitters: the part people forget

Headphones receive. A transmitter sends. You need at least one, and the number depends on how many separate things people might listen to.

• One channel — everyone hears the same thing. One transmitter.
• Two channels — two groups in the same space hearing different things. A yoga class split into beginners and advanced; a tour running English on one channel and Mandarin on the other. Still one transmitter on Pro-Gen, which runs two channels.
• Four channels — four DJs, four rooms of a house party, four languages. That’s the Glow LED system.

The ten-headphone kits ship with two transmitters as standard, which covers almost every two-channel setup with a spare.

Range is up to 30 metres. For a hall, a studio, a classroom or a tour group moving together, one transmitter position covers it. For a long thin space or a site spread across a park, mention it when you enquire — the answer is usually to move the transmitter with the group rather than to buy more.

Microphones: ask yourself who talks

If anybody needs to speak — instructor, guide, celebrant, MC, teacher — you need a microphone transmitter. It mixes the voice into the music automatically, so the music keeps playing underneath while they talk. No mixer, nothing to patch together.

One per person who speaks. Two instructors running two channels need two.

This is the single most common thing people leave off an enquiry and then need on the day.

Worked examples

A 40-person yoga class, outdoors, one instructor 40 headphones + 4 spares = 44. One transmitter. One microphone. If you’re splitting beginners and advanced with a second instructor, still 44 headphones — but two microphones, and you’re using both channels.

A wedding, 120 guests, two DJs 120 + 18 spares = 138, LED for the channel indicator so guests can see which DJ they’re on. Two channels minimum, four if the plan includes a quiet channel for the older guests, which is more popular than people expect.

A high school, four classes of 28, one at a time 30 headphones. Not 112. One transmitter, one microphone for the teacher. This is the setup most schools end up buying outright after their second hire.

A walking tour, 25 people, English and Mandarin 25 + 3 spares = 28. Two channels, two microphones, one for each guide. Pro-Gen, because you’re carrying them between sites and the compact ones fold flat.

If you’re between sizes

Round up. The cost difference between 40 and 50 headphones is far smaller than the cost of ten people standing there without one, and per-headphone pricing improves as the number climbs.

If you genuinely can’t judge the numbers, say so when you enquire. “Somewhere between 60 and 90, it depends on RSVPs” is a perfectly workable brief — we’ll quote the range and you can confirm closer to the date.