Split Air Conditioning Cost Calculator
Pick the room size and this sizes the unit for you, then prices the install including the pipe run and condenser siting that quotes so often hide.
Open the calculator →Price your split AC install in 30 seconds
5 steps. Capacity, pipe run, condenser access, brand tier and region.
How this calculator works
Capacity comes first because everything else follows from it. A 2.5kW unit suits a typical UK bedroom; a 5kW unit suits an open-plan space. Fitting a bigger unit than the room needs costs more up front and more every hour it runs, because it short-cycles instead of modulating down.
The two costs quotes most often leave vague are the pipe run and the condenser siting. Both are priced separately here so you can see what an awkward install is actually charging you for.
On F-Gas: anything touching the refrigerant circuit legally requires an F-Gas registered engineer. We do not verify that for you — ask to see the registration and check it on the register itself before work starts.
Split air conditioning cost by capacity (2026)
| Capacity | Typical 2026 cost | Notes |
|---|---|---|
| 2.0kW (~7,000 BTU) | £1,300–£1,900 | Small box room or study, up to ~10 sq m |
| 2.5kW (~9,000 BTU) | £1,500–£2,600 | Bedroom or home office, up to ~14 sq m |
| 3.5kW (~12,000 BTU) | £1,700–£3,000 | Lounge or master bedroom, 15–25 sq m |
| 5.0kW (~18,000 BTU) | £2,000–£3,600 | Open-plan or large room, 25–40 sq m |
| 7.0kW (~24,000 BTU) | £2,400–£4,200 | Very large open-plan, 40+ sq m |
| Pipe run over ~5m | +£150–£400 | Extra refrigerant pipe, insulation and labour |
| Condenser at height | +£100–£600 | Brackets, working at height or scaffold |
Figures match our split air conditioning cost guide. Refrigerant work is legally restricted to F-Gas registered engineers — check the register yourself.
Split AC calculator FAQs
Roughly, 2.0kW to about 10 sq m, 2.5kW to 14 sq m, 3.5kW to 25 sq m and 5.0kW to 40 sq m. Glazing, aspect and how many people use the room all shift it, which is why an installer should ask about the room rather than quote blind.
Not usually. Most installs run off an existing circuit, but a dedicated spur, isolator or consumer-unit way adds £150–£500. Ask whether it is in the quote.
Yes. Every modern split is a reversible heat pump and heats at a SCOP of roughly 4.0–5.1, which makes it cheaper per unit of heat than direct electric heating.
More refrigerant pipe and insulation, more labour, and often more difficult routing. Runs over about 5m add £150–£400, and long vertical runs in flats add most.
Related cost guides
- Split AC cost guide — the full 2026 breakdown by capacity
- Multi-split costs — several rooms off one condenser
- Running costs — what it costs per hour and per summer
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