Independent · No sales agenda Stop guessing.
Stop guessing.
Size it right.
Four questions, one honest answer — the exact BTU your room needs, what it should cost installed, and which unit to buy.
Size it rightRoom → exact BTU
IndependentSpecs, not a sales pitch
Free & instantNo signup, runs in your browser
Three ways to decide
Whether you’re sizing one room or comparing brands for a whole-home system, start here.
SizingWork out what size mini-split you need — enter your room, ceiling, climate and sun to get the exact BTU capacity and the matching 9k–36k unit size. Best & CompareCompare the best mini-splits and ductless brands — by BTU, SEER2, HSPF, zones, cold-climate performance, DIY-friendliness, warranty and price. BrandsThe major US mini-split brands at a glance — Mitsubishi, Daikin, MrCool, Pioneer, Senville, LG, Fujitsu, Gree and Cooper&Hunter — with specs, cost angle and where each fits.
Why btuwise
- Sizing first: most mini-splits are bought the wrong size. The BTU calculator turns your room, climate, ceiling and sun into the exact capacity you need — and shows the per-square-foot math so you can see why.
- Honest comparisons: the best-and-compare guides line brands up by BTU, SEER2, cold-climate heat, zones, DIY-friendliness, warranty and price — so you see the trade-offs, not just a badge.
- DIY or pro, your call: pre-charged systems like MrCool DIY are genuinely homeowner-installable; anything that needs the lines vacuumed and charged belongs to a licensed pro. btuwise says which is which.
btuwise gives carefully built planning estimates for information only. Oversize a mini-split and it short-cycles; undersize it and it never keeps up. A pro install needs a licensed HVAC contractor (EPA-608 for refrigerant) and a licensed electrician for the circuit. Confirm sizing, cost and code with a local pro before you buy or install.