Get the right size mini-split the first time

Answer a few questions about each room and your climate — we’ll calculate the BTUs you need and what size unit to buy.

Sizing tips that matter

Bigger isn’t better

An oversized mini-split cools too fast and shuts off before it removes humidity, leaving the room cold and damp. Right-sizing beats over-sizing.

Sun and insulation swing it a lot

A south-facing room with poor insulation can need 20–30% more capacity than an identical shaded, well-insulated room next door.

Multi-zone shares one outdoor unit

Sizing several rooms at once lets you compare a multi-zone system (one outdoor unit, several indoor heads) against separate single-zone units.

Common questions

British Thermal Units per hour — a measure of how much heat a unit can add or remove. More BTUs means more heating/cooling capacity, not necessarily better comfort if it’s oversized for the room.

Round up to the nearest standard size (this tool does that automatically). A small amount of extra capacity is fine; a lot of extra capacity causes short-cycling.

It’s a solid rule-of-thumb estimate for shopping and budgeting. For a final purchase, especially on a multi-zone system, have a licensed HVAC contractor run a proper Manual J load calculation.

No — the range shown is equipment only. Installation (line sets, electrical, mounting) typically adds several hundred to a few thousand dollars depending on the job.

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