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Mini Split Cost Guide

Cost by size

Mini Split Cost by Size (BTU & Zones)

Mini split cost rises with capacity (BTU) and the number of zones. A single 12,000 BTU room unit runs about $3,300-$4,800 installed; a 5-zone whole-home system runs $14,000-$25,000.

National estimates. For your city, see cost by city. Methodology.

Single-zone cost by BTU (national)

CapacityTypical roomEstimated installed cost
9,000 BTUup to ~400 sq ft$3,000 - $4,200
12,000 BTU~450-550 sq ft$3,300 - $4,800
18,000 BTU~700-900 sq ft$3,900 - $5,800
24,000 BTU~1,000-1,400 sq ft$4,400 - $7,000
36,000 BTU~1,500-2,000 sq ft (open)$5,200 - $8,500

Multi-zone cost by zone count (national)

ZonesBest forEstimated installed cost
2 zonesTwo rooms or a small home$6,500 - $10,500
3 zonesSmall-to-mid home$8,500 - $13,000
4 zonesMost of a mid-size home$10,500 - $15,500
5+ zonesWhole house$14,000 - $25,000

How to size a mini split

Start at roughly 20-30 BTU per square foot, then adjust up for poor insulation, high ceilings, heavy sun, or cold climates. Undersizing leaves rooms uncomfortable; oversizing short-cycles and wastes energy. Try our sizing calculator, then have an installer confirm with a Manual J load calculation.

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Frequently asked questions

What size mini split do I need?

A rough rule is 20-30 BTU per square foot of conditioned space, adjusted for insulation, ceiling height, sun exposure, and climate. A 12,000 BTU unit suits roughly a 450-550 sq ft room. Use our sizing calculator for a starting estimate, then confirm with an installer's load calculation (Manual J).

Does a bigger BTU unit cost more?

Yes. Higher capacity means a larger compressor and indoor head, so equipment and installed cost rise. But an oversized unit short-cycles and wastes money, so bigger is not better. Match capacity to the room.

How much does a multi-zone mini split cost?

Multi-zone systems share one outdoor unit across several indoor heads. Two zones typically run $6,500-$10,500 installed nationally; three to four zones run $9,000-$15,500; five-plus-zone whole-home systems run $14,000-$25,000.