Badger SaunaMadison, Wisconsin
Wisconsin sauna utility costs

The cheapest sauna starts after nine.

On time-of-use plans, MG&E and Alliant price power by the hour. The same session can cost three times as much at 6 p.m. on a weekday as it does at midnight.

See Every Rate Period How It's Calculated
2026 tariffs checked October 10, 2026MG&E and Alliant Energy

6 kW heater, 45-minute session

$0.31 → $0.97

Alliant low (9.51¢/kWh) up to Alliant high (29.91¢/kWh) on winter rates. Same heater, same sauna. The difference is the hour.

A winter weekday6 kW · 45 min · 20°F outside
MG&ERg-2A time-of-use · Oct–May
$0.45$0.76–$0.77$0.45
AlliantRg-5 time-of-use · Dec–Feb
$0.31$0.68$0.97$0.68$0.31
Weekends and holidays bill at the low rate all day on both.
20°F
Sets the weather. The switch sets the tariff season.
Heater cycling

It doesn't run every minute.

Full power until the room is hot, then the thermostat cycles it. At 20°F outside it's on about 71% of the time. The colder it is, the more it runs.

HeaterHeat-up45 min insideHeater on
4.5 kW · 5′ × 5′ barrel48 min 3.6 kWh2.3 kWh vs. 3.4 at full power68%
6 kW · 6′ × 6′ barrel55 min 5.5 kWh3.2 kWh vs. 4.5 at full power72%
9 kW · 7′ × 8′ barrel55 min 8.3 kWh4.9 kWh vs. 6.8 at full power73%

Each heater in a barrel it's sized for, held at 176°F. Same model as the sauna calculator, ±20%.

Big number 45 minutes inside, heater cycling Below it: per minute · at full power, the most it can cost · the heat-up before you get in

Effective January 1, 2026

Madison Gas and Electric

Winter rates
October 1 through May 31
Summer rates
June 1 through September 30
Rate period4.5 kW5′ × 5′ barrel6 kW6′ × 6′ barrel9 kW7′ × 8′ barrel
Winter peak · October 1 through May 31
Rg-2A · On-peak 110 a.m.–1 p.m. weekdays23.63¢ per kWh $0.541.21¢ a minute$0.80 at full power+$0.85 to heat up $0.771.70¢ a minute$1.06 at full power+$1.30 to heat up $1.162.58¢ a minute$1.60 at full power+$1.95 to heat up
Rg-2A · On-peak 21–6 p.m. weekdays23.34¢ per kWh $0.541.19¢ a minute$0.79 at full power+$0.84 to heat up $0.761.68¢ a minute$1.05 at full power+$1.28 to heat up $1.152.54¢ a minute$1.58 at full power+$1.93 to heat up
Rg-2A · On-peak 36–9 p.m. weekdays23.78¢ per kWh $0.551.21¢ a minute$0.80 at full power+$0.86 to heat up $0.771.71¢ a minute$1.07 at full power+$1.31 to heat up $1.172.59¢ a minute$1.61 at full power+$1.96 to heat up
Winter off-peak · October 1 through May 31
Rg-2A · Off-peak9 p.m.–10 a.m. weekdays, all weekend and holidays13.99¢ per kWh $0.320.71¢ a minute$0.47 at full power+$0.51 to heat up $0.451.01¢ a minute$0.63 at full power+$0.77 to heat up $0.691.52¢ a minute$0.94 at full power+$1.15 to heat up
No time-of-use
Rg-1 · Any hourAll hours, all year18.43¢ per kWh $0.420.94¢ a minute$0.62 at full power+$0.67 to heat up $0.601.33¢ a minute$0.83 at full power+$1.01 to heat up $0.902.01¢ a minute$1.24 at full power+$1.52 to heat up
  • Rg-2A: Optional for any residential customer. MG&E moves time-of-use to a new structure on January 1, 2027.
  • Rg-1: The default residential rate. Same price at every hour.
Effective January 1, 2026

Alliant Energy (Wisconsin Power and Light)

Winter rates
December, January and February
Summer rates
June, July and August
Rate period4.5 kW5′ × 5′ barrel6 kW6′ × 6′ barrel9 kW7′ × 8′ barrel
Winter peak · December, January and February
Rg-5 · High5–9 p.m. weekdays29.91¢ per kWh $0.691.53¢ a minute$1.01 at full power+$1.08 to heat up $0.972.15¢ a minute$1.35 at full power+$1.65 to heat up $1.473.26¢ a minute$2.02 at full power+$2.47 to heat up
Rg-5 · Regular6 a.m.–5 p.m. and 9–11 p.m. weekdays21.01¢ per kWh $0.481.07¢ a minute$0.71 at full power+$0.76 to heat up $0.681.51¢ a minute$0.95 at full power+$1.16 to heat up $1.032.29¢ a minute$1.42 at full power+$1.73 to heat up
Winter off-peak · December, January and February
Rg-5 · Low11 p.m.–6 a.m. weekdays, all weekend and holidays9.51¢ per kWh $0.220.49¢ a minute$0.32 at full power+$0.34 to heat up $0.310.69¢ a minute$0.43 at full power+$0.52 to heat up $0.471.04¢ a minute$0.64 at full power+$0.78 to heat up
No time-of-use
Rg-1 · Any hourAll hours, all year17.01¢ per kWh $0.390.87¢ a minute$0.57 at full power+$0.61 to heat up $0.551.23¢ a minute$0.77 at full power+$0.94 to heat up $0.831.85¢ a minute$1.15 at full power+$1.40 to heat up
  • Rg-5: The default for new homes (unless the service is 320 amps or more). In March–May and September–November there is no high-rate window: weekdays from 6 a.m. to 11 p.m. bill at the regular rate, and nights and weekends at the low rate.
  • Rg-1: Same price at every hour.
  • Rd-1 (demand rate, the default for new 320-amp services) isn't in the matrix. Its energy prices are 4¢ lower than Rg-5's, but it adds $5.88 per kW of your highest weekday hour between 10 a.m. and 8 p.m. One 45-minute 9 kW session inside a clock hour in that window sets a 6.75 kW peak: $39.69 on that month's bill. The tariff caps demand charges at 8.1¢ per kWh of the month's total use. Outside that window Rd-1 is the cheapest of the three.
  • Fuel adjustment is $0.00000 for the 2026 fuel plan. October 2026 alone carries a one-month credit of $0.00788 per kWh (docket 6680-FR-2025).
How it's calculated

Tariff price, modeled heater.

Download the full matrix as JSON, with every tariff charge and computed cost.

  • The heater doesn't run every minute. It runs flat out until the room reaches temperature, then the thermostat switches the elements off and on to hold it. Each heater is modeled in a barrel it's sized for (solid wood staves, a 10 sq ft glass door), held at 176°F, at the outside temperature set on the slider (20°F to start). The big number in each cell is the 45 minutes you spend inside, with the heater cycling.
  • Cycling cuts less than you'd expect in cold weather: at 20°F the heater still runs about 70% of the time, because the wood walls keep soaking up heat for the first hour. On a 90°F day it's under half. A second hour costs less again.
  • Under the big number: the same 45 minutes at full rated power, which is the most it can cost, and the cost of the heat-up before you get in, at the same rate.
  • Full power per minute = heater kW ÷ 60 × the period's ¢ per kWh. Cycling multiplies that by the share of time the heater is on.
  • Winter and summer are each utility's own tariff seasons, which aren't the same months. The switch picks the price; the slider picks the weather, so you can price a cold October evening on MG&E's winter rates or a mild one.
  • Per-kWh charges only. Fixed daily charges (MG&E $0.49315, Alliant $0.5260 single-phase) are on the bill whether or not the sauna runs, so they're left out. So is sales tax.

For kWh at every outdoor temperature from 80°F down to −20°F, see how much electricity a sauna uses.