Mobile sauna is high-margin per session — but startup is the highest of any rental category. Here's the honest math.
One-time startup (year 1)
- Sauna unit (trailer-mounted): $15,000-$35,000
- Tow vehicle (if not owned): $0-$25,000
- Setup gear (stabilizers, towels, robes, music speaker): $1,500-$3,000
- Cold plunge tub (optional, recommended): $300-$1,500
- Insurance (general liability + auto + waiver template): $1,500-$2,500
- LLC + business license: $150-$300
- Booking page + software (annual): $300
- Initial wood / fuel / cleaning supplies: $200-$400
- Photo shoot for marketing: $200-$500
Total year-1 (with owned tow vehicle): ~$19,000-$43,000. With dedicated truck: $25,000-$60,000.
Recurring (steady state)
- Insurance: $125-$250/month
- Wood / fuel / propane: $100-$400/month
- Cleaning supplies + sanitizer: $30-$80/month
- Software: $30-$80/month
- Vehicle gas + maintenance: $200-$500/month (peak season)
- Phone (business line): $25-$50/month
- Marketing (Instagram boosts, retreats partnerships): $50-$300/month
- Accountant (averaged): $30-$100/month
- Equipment maintenance fund: $100/month
Total: ~$700-$1,800/month. Call it $1,200/mo average.
Annual + occasional
- Sauna unit deep-clean / refurbish: $300-$800/yr
- Stove / heater service: $150-$400/yr
- Tax prep: $400-$800
- License renewal: $100-$200
- Vehicle major repair fund: $1,000-$2,000/yr
- Replacement towels + accessories: $200-$500/yr
Hidden costs
- Off-season cash flow gap (May-Sept lull): need 3-month buffer.
- Quote-to-no-book ghosting: 30-40% of inquiries.
- Damage / repairs (rare but real): wood unit fires happen; insurance covers but deductible adds up.
- Towel + robe loss / theft: $200-$500/yr.
Take-home math (gross $80K/yr)
- Gross: $80,000
- Recurring monthly ($1,200 × 12): -$14,400
- Annual + occasional: -$2,500
- Hidden (5%): -$4,000
- Self-employment tax: -$8,500
- Federal income tax (~12%): -$5,500
- State income tax: -$2,000
- True take-home: ~$43,100
$80K gross = $43K net. At $150K gross? About $85K net.
Improving margin
- Add a cold plunge — single highest-margin upsell.
- Lock in athlete team contracts — recurring smooths revenue.
- Pursue corporate days — $1,500-$3,000 per booking.
- Tighten service zone — less drive time per session.
The bottom line
Sauna is high-margin per session but capital-intensive at startup. Plan for $20K+ startup + $1,200/mo recurring + 35% of net to taxes. Operators who hit $80K gross net ~$43K — comfortable as a side business, modest as full-time. The path to $150K+ is corporate + retreats + recurring contracts.