Will it fit? The three measurements to take before you buy a sauna or cold plunge
Buyer guide · Updated Oct 19, 2026 · Figures from the linked maker and retailer pages
Most people measure the spot where the sauna will stand and stop there. That's one of three checks. The other two (getting it to that spot, and whether the floor can hold it) are where installs actually go wrong.
1. The room: footprint, clearance, headroom
- Use the outside (assembled) size. Example: Almost Heaven's Auburn indoor sauna is 69⅞ × 47⅛ × 77⅝ in. outside (maker page).
- Add the maker's clearance. Almost Heaven's FAQ says at least 2 in. from walls, especially where the vents are. Plunge asks for 16 in. on the fan side of the All-In, 12 in. in front and 4 in. on the left (maker page). So a 76¾ in. long tub really needs about 97 in. of wall.
- Leave headroom to assemble. Indoor kits go together by tipping panels upright. If your ceiling is within a few inches of the sauna's height, read the assembly manual before you order.
- Some pages don't publish the assembled size at all. The Almost Heaven BlackWater Mini-Cube page we checked lists the shipping size (90 × 45 × 45 in., 745 lb) but not the assembled size. Ask before you buy.
2. The path in: doorways, gates, stairs
Compare your narrowest opening with the shipping crate or the largest single panel. Published crate sizes we found:
| Product | Crate | Weight | Source |
|---|---|---|---|
| Finnmark FD-2 (indoor infrared) | 78 × 36 × 50 in. | 441 lb | Topture |
| SaunaLife CL3G (outdoor cube kit) | 70.9 × 43.3 × 32.3 in. | 990 lb | SaunaLife |
| Dundalk Harmony barrel | 84 × 45 × 34 in. | 1,044 lb | Topture |
| Almost Heaven BlackWater Mini-Cube | 90 × 45 × 45 in. | 745 lb | Almost Heaven |
Two things surprise buyers:
- Curbside means curbside. Freight carriers generally drop the crate at the curb or the end of the driveway. The retailer page for the Dundalk Harmony says the customer offloads it, often with a forklift or a rented tilt-bed truck.
- One-piece cold plunges can't be taken apart. The Plunge All-In is 31½ in. wide and 28¾ in. tall, so it needs an opening at least 28¾ in. wide on its side. Inflatables (Plunge Air, Plunge Chill tubs) pack down small.
3. The floor: filled cold plunges are heavy
Water weighs about 8.34 lb per gallon. Makers' own filled weights: Plunge All-In 1,150 lb (105 gal), Plunge Pod 820 lb (87 gal), Ice Barrel 300 700 lb (77 gal). Spread over a small footprint, that's often more than 40 lb per sq ft, the live load floors and decks are commonly designed for (IRC Table R301.5; figure as cited by third-party guides, not checked against the code text). A concrete slab or ground pad is fine. On a deck, a wood floor or upstairs, ask a structural pro.