Most of a hot tub’s running cost is the heater keeping the water at around 38–40 °C, which depends on the weather, the cover and how often it is used. Typical heaters are 3–5.5 kW and circulation pumps 0.2–1.5 kW. A good insulated cover can cut heating costs by half.
How to use the Hot Tub Cost Calculator
- Heater power
- Heating hours per day
- Pump power
- Pump hours per day
- Electricity price
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the heater power and how many hours a day it heats, the pump power and its daily run time, and your electricity price.
Tips
- Use the figures from your own bills and product labels – prices and appliance ratings vary widely.
- Look at yearly totals: small daily costs add up and make it easier to compare options.
- Round quantities up to whole packs, rolls or bulbs when you shop.
- Re-check the numbers when prices change; most results scale directly with the unit price.
Common mistakes to avoid
- Confusing watts (power) with watt-hours or kilowatt-hours (energy).
- Comparing prices without bringing them to the same unit first.
- Ignoring one-off costs such as installation, delivery or replacement parts.
Inputs explained
| Field | What to enter |
|---|---|
| Heater power | Units: W, kW, hp |
| Heating hours per day | A number |
| Pump power | Units: W, kW, hp |
| Pump hours per day | A number |
| Electricity price | Units: /kWh |
What each result means
- Energy per day = ([Heater power]×[Heating hours per day] + [Pump power]×[Pump hours per day])÷1000
- Cost per day = [Energy per day]×[Electricity price]
- Cost per month = [Cost per day]×30.44
- Cost per year = [Cost per day]×365.25
Example values
How the main result changes when Heater power changes and everything else stays at the example values above:
| Heater power (W) | Cost per month |
|---|---|
| 2,000 | 37.02 |
| 3,000 | 51.63 |
| 4,000 | 66.24 |
| 5,000 | 80.85 |
| 6,000 | 95.46 |
| 8,000 | 124.68 |
Formula
Daily cost = (heater kW × heating hours + pump kW × pump hours) × priceMonthly = daily × 30.44Worked example
Inputs — Heater power: 4,000 W; Heating hours per day: 3; Pump power: 400 W; Pump hours per day: 4; Electricity price: $0.16 /kWh.
Results — Energy per day = 13.6 kWh; Cost per day = $2.18; Cost per month = $66.24; Cost per year = $794.78.
Frequently asked questions
How much does it cost to run a hot tub?
Typically $25–$60 a month in electricity, more in cold climates or with a poor cover.
Should I turn my hot tub off when not using it?
Usually no – reheating from cold uses a lot of energy; lower the temperature a few degrees instead.
Does a cover make a difference?
Yes – a thick, well-fitting cover is the single best way to cut running costs.
What formula does the Hot Tub Cost Calculator use?
Daily cost = (heater kW × heating hours + pump kW × pump hours) × price.