The best mini splits by size (9k to 36k BTU)

Get your target first: the sizing calculator turns your room's real inputs into a BTU number in two minutes, and the sizing guide explains what it's weighing.

Best 9,000 BTU mini split (small rooms, ~300-450 sq ft)

For a bedroom, office, or small addition:

• Best overall / DIY: MRCOOL DIY 5th Generation 9k 115V - 115V, self-installable, the easiest small-room path.
• Best value: Senville AURA 9k 230V - high certified efficiency and cold-climate operation for a professional install.
• Best efficiency: GREE Vireo R32 9.1k 230V.

Best 12,000 BTU mini split (~450-550 sq ft, the most common size)

The workhorse size for a living room, primary bedroom, or small open plan:

• Best overall / DIY: MRCOOL DIY 5th Generation 12k 115V - 115V and self-installable, strong certified heating efficiency.
• Best value: Senville AURA 12k 230V - certified SEER2 in the mid-25s, near the premium benchmark, at a value price.
• Best efficiency line: GREE Vireo R32 12k 230V; budget option GREE Livo R32 12k 230V.

Best 18,000 BTU mini split (~700-1,000 sq ft)

For a large living room, open-plan space, or small apartment:

• Best value: Senville AURA 18k 230V.
• Best DIY: MRCOOL DIY 5th Generation 18k 230V (and the MRCOOL DIY 5th Gen Hyper Heat 18k 230V for cold climates).
• Best efficiency: GREE Vireo R32 18k 230V.

Best 24,000 BTU mini split (~1,000-1,400 sq ft)

For a great room, large open plan, or small whole-floor:

• Best value: Senville AURA 24k 230V.
• Best DIY: MRCOOL DIY 5th Generation 23k 230V.
• Best efficiency: GREE Vireo R32 22k 230V; budget GREE Livo R32 24k 230V.

Best 36,000 BTU mini split (large spaces)

For a big open area or shop:

• Best DIY: MRCOOL DIY 5th Generation 36k 230V.
• Best value: GREE Livo R32 33.6k 230V.

At this capacity, also weigh whether a multi-zone system split across rooms serves you better than one large head in a single space.

Don't skip the load calculation

Square footage is a starting point, not the answer. A sunny, poorly insulated, or high-ceilinged room needs more capacity than its area suggests; a tight, shaded room needs less. Oversizing is the common mistake - a too-big unit short-cycles, dehumidifies poorly, and wears faster. Always confirm with the sizing calculator.

How we picked

Every model is verified against manufacturer documentation and AHRI certificates - including checking that a "24k" certifies its rated capacity - and where marketing disagrees with the certificate we publish the certified number. We don't take payment for placement. Compare any of these head to head, or filter by size and efficiency, in the product finder.

FAQ

What size mini split do I need for 500 sq ft? Roughly a 12,000 BTU unit for an average, well-insulated room - but sun, ceiling height, and climate can move it up. Confirm with the sizing calculator.

What's the best 12,000 BTU mini split? The MRCOOL DIY 12k for self-install, or the Senville AURA 12k for near-premium efficiency on a professional install.

How many square feet does an 18,000 BTU mini split cool? Roughly 700-1,000 sq ft as a starting range, depending on insulation, windows, and climate - size to the load, not just the area.

Can a mini split be too big for the room? Yes, and it's the usual mistake. Oversized units short-cycle, remove less humidity, and wear faster. Right-sizing beats oversizing every time.

Sources

• AHRI: AHRI Directory public details for GREE Livo/Vireo R32 pairings - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• AHRI: AHRI certificate 214779350 for LIV12HP230V1R32AO / LIV12HP230V1R32AH - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE DFS warranty statement for units installed after 2021-12-31 - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE Licensed Contractor Warranty Program - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE Livo R32 submittal 12MBH 230V - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: Livo R32 Installation and Owner's Manual - Outdoor Unit - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• HVACDirect: HVACDirect product page GREE Livo R32 12,000 BTU (230V) - GREE Livo R32 12,000 BTU (230V), retrieved Jul 21, 2026.
• AHRI: AHRI Directory public details for GREE Livo/Vireo R32 18k/24k pairings - GREE Livo R32 24,000 BTU (230V), retrieved Jul 21, 2026.
• AHRI: AHRI certificate 214779349 for LIV24HP230V1R32AO / LIV24HP230V1R32AH - GREE Livo R32 24,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE DFS warranty statement for units installed after 2021-12-31 - GREE Livo R32 24,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE Licensed Contractor Warranty Program - GREE Livo R32 24,000 BTU (230V), retrieved Jul 21, 2026.
• GREE Comfort: GREE Livo R32 submittal 24MBH 230V - GREE Livo R32 24,000 BTU (230V), retrieved Jul 21, 2026.