Advice · 3 min read · Updated 6 November 2026
What size hot tub should I hire? How many people really fit
Advertised versus comfortable capacity
Capacity figures for inflatable hot tubs are generous. They assume people sitting close together with legs interlocking. For comfort, especially for adults, take one or two people off the advertised figure.
| Advertised size | Comfortable for adults | Typical outside diameter or size | Typical water volume |
|---|---|---|---|
| 2 to 4 person inflatable | 2 to 3 | Around 1.5 to 1.8 m | Around 600 to 800 litres |
| 4 to 6 person inflatable | 3 to 4 | Around 1.8 to 2.1 m | Around 800 to 1,100 litres |
| 6 to 8 person inflatable | 4 to 6 | Around 2 to 2.3 m | Around 1,000 to 1,300 litres |
| 5 to 6 seat hard-shell | 4 to 5 | Around 2 m square | Around 1,200 to 1,600 litres |
| 7 seat hard-shell | 5 to 6 | Around 2.1 to 2.3 m square | Around 1,500 to 1,900 litres |
Sizes and volumes vary between models, so check the exact tub with your supplier before booking.
Work out how many will use it at once
- Count the adults who will want to get in at the same time, not everyone at the party
- Remember that many people use a hot tub for 15 to 20 minutes and then get out
- Allow more room for tall adults, larger guests and anyone with mobility needs
- Think about whether people want space to relax or are happy to squeeze in for a short time
- Children should be closely supervised and not packed in with a group of adults
Bigger is not always better
A larger tub needs more space, a larger flat base, more water and longer to heat. It also weighs more when full. A 6 to 8 person inflatable with people in it can easily weigh around 1.3 tonnes or more. Make sure your base can take it and that you can reach a suitable socket without an extension lead.
- More water means a longer first heat and higher electricity use
- A bigger footprint needs a larger level area plus space to walk around
- More bathers means the water needs testing and treating more often
- Hard-shell tubs need wider access to get into the garden
Planning for parties
For parties, rotation works better than a giant tub. A simple rota keeps the water cleaner, keeps sessions safe and stops one group taking over.
- Plan sessions of around 15 to 20 minutes per group
- Have towels, dressing gowns and a warm changing area ready
- Ask everyone to shower or rinse before getting in
- Test the water before the party, at least once during it, and afterwards
- Keep drinks in plastic cups and away from the water, and avoid alcohol in the tub
- Agree an end time so the cover goes back on overnight
Space around the tub
Leave at least a metre or so of clear space around the tub where possible, for getting in and out safely, for the steps and for the supplier to reach the pump and controls. Plan where wet feet will go, as a slippery path to the back door is one of the most common causes of accidents. Outdoor mats or a non-slip surface help.
Check overhead too. Avoid low branches, washing lines and overhead cables, and do not place the tub directly under trees that drop leaves and sap into the water.
Sizing for families
For a family of four with younger children, a 4 to 6 person inflatable is usually plenty. Children should only use hot tubs at a lower temperature and for shorter times, so the effective capacity for adults is what matters most. For larger families or groups of adult friends, a hard-shell tub with moulded seats is more comfortable, as everyone gets their own space.
If you are unsure between two sizes, think about how the tub will be used most of the time rather than on the busiest evening. A tub that is comfortable for the usual two or four people, used in rotation for the occasional party, is often the best balance of cost, heating time and space.
Measure the space before you decide. Mark out the tub's diameter or footprint on the ground with string or chalk, add room for the steps and walking space, and check it still leaves a safe path to the house.
Frequently asked questions
How many people can actually fit in a 6 person inflatable hot tub?
Four adults can usually sit comfortably in a 6 person inflatable, and five or six can fit for short sessions if they do not mind being close. Advertised capacities assume tight seating. If you have several tall or larger adults, or want everyone to stretch out, choose the next size up or a hard-shell tub with moulded seats.
What size hot tub should I hire for a party of 20?
You do not need a tub for 20 people at once. Most guests use a hot tub in short turns, so a 6 to 8 person inflatable or a 6 to 7 seat hard-shell tub, run with sessions of around 15 to 20 minutes, usually works well. Make sure the water is tested before, during and after the party.
Do bigger hot tubs cost more to hire?
Usually, yes. Larger inflatables and hard-shell tubs typically cost more to hire, take longer to heat and use more electricity because they hold more water. The difference is often small for inflatables, but hard-shell tubs are a step up in price. Ask the supplier for prices on two sizes so you can compare.
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