Guides · How-to
How Much Electricity Does a Heated Cat House Use? (With Monthly Cost Math)
Short answer: very little. Even running nonstop for a month, a typical 20 to 40 watt pad uses about 14 to 29 kWh, a few dollars at typical U.S. rates. Here's the math so you can work it out for your own pad and rate.
The formula
Energy used (kWh) = watts × hours ÷ 1,000. A month of round-the-clock use is about 720 hours (24 × 30). Multiply the kWh by your electricity rate, which is on your bill in cents per kWh.
Maximum monthly use by pad size
These are worst-case numbers, with the pad drawing its full rated wattage every hour of the month. The cost column uses 18 cents per kWh as an example; swap in your own rate.
| Pad rating | Per day (max) | Per 30 days (max) | Cost at 18¢/kWh |
|---|---|---|---|
| 20 W (typical single-cat pad) | 0.48 kWh | 14.4 kWh | about $2.59 |
| 35 W (larger single or 2-cat pad) | 0.84 kWh | 25.2 kWh | about $4.54 |
| 40 W (multi-cat pad) | 0.96 kWh | 28.8 kWh | about $5.18 |
Over a five-month season (November through March, 151 days), a 35W pad tops out at about 127 kWh, roughly $23 at 18¢/kWh.
Why real use is usually lower
- Thermostatic pads idle at a low setting when no cat is lying on them, so they draw well under their rating much of the day.
- Constant-temperature pads cycle on and off to hold their set point. Insulated, foil-lined walls and a covered location mean less cycling.
- Seasonal use: many people unplug on mild days or once spring arrives.
How to measure your own
A plug-in electricity usage monitor (about the size of a phone charger) sits between the outlet and the pad and shows the actual kWh used. Leave it for a week, multiply by about 4.3 for a monthly figure, and you'll know exactly what your shelter costs. Make sure any monitor you use outdoors is rated for outdoor use, or measure indoors in a garage.
Ways to keep the cost down
- Put the shelter in a covered, wind-sheltered spot so the pad works less.
- Choose a well-insulated shelter with a raised floor; cold ground pulls heat out of the pad.
- Keep the pad cover on and the bedding dry.
- Pick the size you need: a 40W multi-cat pad for one cat wastes energy, and a shelter that's too big is harder to keep warm.
Bottom line
Budget a few dollars a month per shelter, and less if the pad is thermostatic and the shelter sits out of the wind.
Floor raised about 5–6 in, room for 1–3 cats, two doors and three windows, and a 32–35W pad that holds about 100°F with its cover on. Sold by Depoodeal with free U.S. shipping and 30-day returns.
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