Phone Farm Power Consumption & Heat Calculator
How much electricity does a phone farm use, what does it cost and how much heat goes into the room? Enter your phones and your electricity price.
A phone farm runs around the clock, so its power bill is the number of watts times 730 hours a month times your electricity price. Every watt also ends up as heat in the room. The calculator below does the maths; the only number you need to bring is what your own rack draws, which a plug-in power meter shows you in a day.
Power and heat of your phone farm
Power per device (example values, change them to yours)
- 20 phones × 3 W
- 60 W
- 1 rack × 15 W
- 15 W
- 1 computer × 30 W (up to 40 phones each)
- 30 W
- Per phone and month
- $0.77
- Per year
- $184
How do I work out what a phone farm uses?
Three things draw power: the phones, the rack around them (fans and USB hubs) and the computer that runs the farm. Add their watts, multiply by 24 hours and about 30.4 days, and you have kilowatt-hours per month. Multiply that by your electricity price and you have the monthly bill.
The values in the calculator are examples to show how the numbers move, not measurements. Phones draw very different amounts depending on the model, the screen brightness and what they are doing, so measure your own rack before you rely on the result.
How do I measure my own rack?
Plug the whole rack, phones charging and running as usual, into a plug-in power meter and leave it for a full day. Read the average watts, not the peak when everything boots at once. Do the same for the computer. Enter both into the calculator and you have your real numbers.
For the computer, Apple lists 155 W as the maximum continuous power of the current Mac mini. A Mac running a farm sits far below that most of the time, which is why the meter matters more than the label.
How much heat does a phone farm make?
All of it. Every watt the farm draws turns into heat in the room, at 3.412 BTU per hour per watt. That is why racks have fans, and why a farm in a small closed room gets warm. Phones that run hot all day throttle and drop connections, so give the rack space to breathe and keep the room ventilated.
What else should I plan for?
- Leave headroom on the circuit. Phones charging after a power cut or a restart all draw at the same moment.
- Keep the computer on. A farm only runs while its Mac or PC is awake; turn sleep off.
- Count power into the total cost. Hardware, software and connectivity are in how much a phone farm costs; the computer is in which Mac mini you need.
FAQ
How much electricity does a phone farm use?
It depends on the phones, the rack and the computer, so measure your own with a plug-in power meter for a day. Then multiply the average watts by 730 hours for a month.
How much heat does a phone farm produce?
Every watt becomes heat: 3.412 BTU per hour per watt. A farm that draws 200 W heats the room like a 200 W heater.
How much power does a Mac mini use?
Apple lists 155 W as its maximum continuous power. Running a farm, it usually draws much less; a power meter shows the real value.
Ready to run real phones?
Buy a 20-phone farm box, rent a hosted rack, or run our control software on hardware you already own.
