Topic
Sizes and shapes
Round tubs are the classic shape and usually hold fewer litres for the same width. Square tubs give more seating space in the corners and suit decking, but hold more water to heat.
- 2 to 4 bathers
- About 600 to 800 litres
- 6 to 8 bathers
- About 900 to 1,100 litres
The outer size on the box includes the thick inflated wall, so the inner diameter or inner length and width is what you actually sit in. A 180 cm round tub may have an inner diameter of only about 130 cm.
More litres means longer heating and more kWh. The water volume calculator works out litres, UK gallons, filled weight and fill time from the inner size and the water depth.
Measure the space with room to walk round the tub, reach the pump unit and lift the cover off. A square tub fits neatly against a fence or the edge of decking.
Common mistakes
- Measuring the garden for the outer size and forgetting room to step in and out.
- Reading the bather number as comfortable seats for adults.
Guides on this topic
- Round vs square inflatable hot tubsRound vs square inflatable hot tubs compared on seating space, footprint, water litres and patio fit, with the volume worked out for both shapes.Comparison
- Inflatable hot tub sizes and water volumesInflatable hot tub sizes explained: a chart of outer sizes, water litres, gallons and seats for common models, plus how much space to leave round the tub.Guide
- How much does a hot tub weigh when full?How much does a hot tub weigh full? Empty weight, water and bathers added up for common inflatable sizes, plus what the load means for your base.Guide
- Hot tub cover sizes: how to measure for a new coverHot tub cover sizes explained: how to measure the outer diameter or length and width, wall height and skirt so a replacement or thermal cover fits.Guide
Buying guides on this topic
- Best 2 to 4 person inflatable hot tubsSmall inflatable hot tubs for two to four people compared on seats, outer size, water litres, jets and heater, using figures from each maker's listing.Buying guide
- Best 6 to 8 person inflatable hot tubsSix and seven seat inflatable hot tubs compared on seats, water litres, outer size, jets and wall build, using the figures each maker lists.Buying guide