Two to four. The size most UK households actually use.

Four adults for a soak — shoulders and torso submerged, back against the bench, a glass of something on the rim. That use case is real. Four adults all getting full directional hydrotherapy simultaneously — jets hitting lumbar, shoulders and neck — is tighter; three adults is the realistic number for that, or four if two of them are children. It's a geometry problem rather than a marketing one: jet banks need physical separation to work, and a 200–215cm tub has four bench positions but only three 'primary' jet arrays.

The honest sizing rule: buy for the number of people who'll use it routinely, not the maximum it theoretically seats. If you're two adults who'll occasionally have a friend round, a 3-seat is fine. Two adults plus two young kids, 4-seat. Regularly 4+ adults several times a week, 5-seat and up.

For a couple, yes — often more so than a 4-seat. A proper 2-seat spa is built as two contoured seats, not 'half of a 4-seat'. That typically means deeper water, a lounger on at least one side for proper horizontal soaking, and jets designed for adult-length legs and backs. The water volume is around 700–900 litres, which heats up quickly and runs at the lowest end of our running-cost figure.

The trade-off is genuinely only the third-person option. If you regularly have a third adult join you — a family member visiting, a friend popping round for an evening soak — a 2-seat won't stretch. A 3-seat does. For two-adult households where 'the neighbours pop over for a soak' is rare, 2-seat is the right call and tends to be the spa people are happiest with after 12 months of ownership.

Roughly:

• 2-seat: 170–190cm square (or 190 × 130cm if it's a slim design), around 75–85cm tall, water volume 700–900 litres.
• 3-seat: 190–200cm square, around 85cm tall, water volume 900–1,100 litres.
• 4-seat: 200–215cm square, around 85–90cm tall, water volume 1,100–1,500 litres.

Exact dimensions vary by model — each product listing carries the full spec. For siting, allow at least 50cm of clear access on one side for filter changes and service, plus room for a cover-lifter arc to pivot back without hitting a wall or fence.

At current UK electricity tariffs, expect £2–£2.50 per day averaged across the year, with our smaller, well-insulated tubs sitting toward the lower end of that range. That's heating the water from cold on first fill, holding 38°C through the year, running the circulation pump 24/7 and operating the jets for a typical domestic soak pattern.

The £2–£2.50/day figure is the range we use across our whole hard-shell collection because once a properly insulated tub is up to temperature, the per-day cost is governed by heat loss through the cover and cabinet, not by water volume. A 2-seat spa's 900 litres and a 6-seat's 1,800 don't need proportionally different wattage to hold — they need similar wattage because they have similar cover surface area. Where the smaller tub wins clearly is first heat-up (half the water volume = half the time) and the embedded cost of the first fill every 4–6 weeks for a water change.

Most of the 2-seat and 3-seat tubs in this collection are plug-and-play 13A — they run from a standard outdoor UK socket on an RCD-protected circuit, no electrician attendance on the day of delivery. Several 4-seat models are also 13A-compatible; some require 32A for the pump spec. Each product listing shows the electrical requirement clearly.

If you have an outdoor socket and no 32A feed, start with a 13A-compatible model — our plug-and-play collection breaks the category down properly. Most of our hard-shell 13A spas can be upgraded to 32A later without buying a new tub.

Yes — most 2-seat spas are built as a lounger + a contour seat, which is often the selling point. In 3-seat and 4-seat tubs it depends on the model; the trade-off is that a full-length lounger eats the space of roughly two bench seats, so a 4-seat with a lounger seats closer to three in practice. If a lounger is the reason you're buying a spa, mention it when ordering and we'll walk you through the specific models in the range that carry one at this size. The adult inseam you need to support matters — a 180cm-tall user needs a different lounger than a 165cm one.

Yes — and in one important way, better. Jet count is a marketing number; what matters is jet placement per seat and pump HP behind each seat. A 2–4 seat spa has 2–4 separate jet arrays, each fed by the same circulation system we put behind the seats on a 6-seat tub. That means the massage on your back isn't softer because there are three seats instead of six — it's the same jet, the same pump pressure, the same directional coverage.

Where a bigger tub has an edge is if you want a different jet pattern to move between during a long session. Some 6-seat tubs have a lounger + two bench seats + a captain's chair, each with a different therapy focus. If that's the reason you're buying, go bigger. If you want one jet bank that works properly for you or you and your partner, a 2–4 seat does the job exactly as well.

Plausibly, around age 13–14. A 4-seat spa with two 180cm+ teenage legs in it gets cramped. The practical patterns we see: families with young kids buy a 4-seat, use it heavily for 6–8 years while the kids are small, and either upgrade to a 5/6-seat when the teenage years land or keep the 4-seat for couples-use and accept that the kids use it less often as they get older.

Neither is wrong. A 4-seat spa that served a family for eight years is still a good buy — it doesn't become a bad purchase retroactively. If you're certain the household will grow and the tub will need to scale with it, buying a 5/6-seat from the start is fine; just be clear-eyed about running it through the years when the kids are still small and the bigger tub is mostly used by two people at a time.

Yes — meaningfully. Our 5″-tapered hard-top covers weigh roughly 15–18kg on a 2-seat, 18–22kg on a 3-seat, and 22–28kg on a 4-seat, against 30–40kg on a 6-seat. That's the difference between a single person lifting the cover one-handed off a hinge and two people needed to handle it without straining a back. Cover lifters make everything easier on any size tub, but on the 6-seat they move from 'nice to have' to 'necessary'; on a 2–3 seat, lifting unaided is realistic.

Yes — same 5″ tapered hard-top cover, same full-foam cabinet, same IR-reflective panelling on our hard-shells. The insulation package is a build spec, not a capacity spec. That's why smaller tubs sit at the lower end of the £2–£2.50/day running-cost range rather than outside it: the steady-state heat loss is driven by cover quality and cabinet insulation, both of which are identical across the range. Real-world insulation check: with all pumps running at full power during a 45-minute soak, our tubs lose roughly 1–2°C; a lesser-insulated tub drops closer to 5°C in the same session, triggering a rapid cool-down. On our spas, most customers go pruney before they go cold.

Please allow up to 10 working days as a realistic ceiling — most in-stock 4-or-less tubs land meaningfully faster from our Redhill, Surrey warehouse. Exact despatch is shown on each product listing. Because most of the smaller tubs are 13A plug-and-play, there's no electrician step between delivery and first use — you can be in the water the evening the spa arrives, heat-up time allowing.

Same manufacturer warranties as our bigger hard-shells — shell structure, cabinet, plumbing and equipment cover, with wear items (filters, jets, pillows, cover fabric) treated as consumables. Warranty length and inclusions vary by model; full per-product terms on each listing. UK support is handled from our Redhill, Surrey office — same team, same phone number, whether you've bought a 2-seat or a 6-seat.