Mini Split for 300 Sq Ft: Size, Cost & Systems
At the standard 20 BTU per square foot baseline, a 300 sq ft space needs about 6,000 BTU of cooling, which lands in the 9,000 BTU class on the standard sizing chart. Our dataset holds 2 verified system(s) here, 2 with first-hand prices from $799.99 to $1,598; the cheapest is the Senville LETO 9k. Of these, 1 state a coverage range that explicitly includes 300 sq ft.
Computed from our dataset
- 2 system(s) from our verified dataset appear on this page.
- Price range: $799.99 to $1,598 (verified 2026-11-04).
- Cheapest: Senville LETO 9k at $799.99 (Senville).
- Highest SEER2: Senville LETO 9k at 21.2 SEER2.
- Best heating rating: Friedrich Floating Air Pro 9k, rated to -4°F.
| System | Zones | BTU | Coverage | SEER2 | Heats to | Install | Price | |
|---|---|---|---|---|---|---|---|---|
| Senville LETO 9k SENL-09CD/220 | 1 | 9,000 | — | 21.2 | 5°F | Pro / flare | $799.99 at Senville | Check price |
| Friedrich Floating Air Pro 9k FPHW091C | 1 | 9,000 | up to 400 sq ft | — | -4°F | Pro / flare | $1,598 at Sylvane | Check price |
Buying notes
- The 20 BTU/sq ft baseline assumes 8-9 ft ceilings, average insulation, and a moderate climate; the sizing guide lists the adjustments (sunrooms run 30-35 BTU/sq ft, kitchens add ~4,000 BTU).
- Oversizing an inverter system slightly is low-risk (it modulates down); oversizing a lot short-cycles and leaves humidity behind.
- If this space is one room of several, compare a multi-zone system before buying a big single-zone - one condenser can serve several handlers.