Free tool · 2026

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 Read the split system cost guide

Free tool

Sized from room areaPipe run pricedBrand tiers compared100% free · no sign-up

Free tool

Price your split AC install in 30 seconds

5 steps. Capacity, pipe run, condenser access, brand tier and region.

Method

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. If you are not sure, run the kW / BTU sizing calculator first.

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 certified engineer. Every engineer Air Con Surrey matches you with is vetted and F-Gas certified — but it is still worth asking to see the certificate before work starts.

2026 costs

Split air conditioning cost by capacity (2026)

Supplied and fitted, mid-range brand, standard install. The calculator adds pipe run, siting, brand tier and region on top.

Capacity	Typical 2026 cost	Notes
2.0kW (~7,000 BTU)	£1,500–£2,000	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 single split air conditioning cost guide. Refrigerant work is legally restricted to F-Gas certified engineers.

FAQs

Split AC calculator FAQs

What size air conditioner do I need?+

Roughly, 2.0kW for up 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 — our kW / BTU sizing calculator works it through, and a good engineer will ask about the room rather than quote blind.

Does the price include electrical work?+

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.

Will a split system heat my room in winter?+

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. Air-to-air systems are not eligible for the Boiler Upgrade Scheme, which covers air-to-water only.

Why is a long pipe run more expensive?+

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.

How accurate is this split system calculator?+

It is a guide price built from 2026 UK supply-and-fit rates, with an 88–115% band around the mid estimate. The real figure depends on your walls, the pipe route and the condenser position, which is why an engineer confirms it after a survey.

Keep reading

❄