Updated 19 October 2026.
The Mac mini M4 can have low electricity use, but its monthly cost depends on the workload, operating hours and your electricity rate. Apple‘s published figures are 4 W at idle and 65 W at maximum load for one tested M4 configuration. Idle is not the same as sleep.
What Apple’s power figures actually describe
Apple’s Mac mini power-consumption table identifies the configurations and measurement conditions. For the 2024 models it lists:
| Tested configuration | Idle | Maximum |
|---|---|---|
| M4, 16 GB unified memory, 256 GB SSD | 4 W | 65 W |
| M4 Pro, 64 GB unified memory, 8 TB SSD | 5 W | 140 W |
Apple defines idle with Finder open and default power-management settings. Those results are reference measurements, not a promise that every configuration or task draws the same power. The power-supply rating in a specification sheet is also not the computer’s constant consumption. Check the 2024 Mac mini specifications when comparing the hardware variants.
Convert watts into energy before calculating cost
Energy in kWh = average watts × hours used ÷ 1,000. Then multiply the kWh result by the price per kWh on your bill. Watts describe power; watt-hours or kilowatt-hours describe energy over time.
For example, 65 W for eight hours is 520 Wh, or 0.52 kWh. Repeating that for 30 days gives 15.6 kWh. It is incorrect to describe the result as “520 watts per day,” and this maximum-load scenario is not a measured average office workload.
Illustrative monthly costs
The following calculations use a sample tariff of $0.20 per kWh, not a current national electricity-price estimate. Substitute your own rate. The 20 W scenario is an example input, not an Apple measurement.
| Scenario | Energy over 30 days | Example cost |
|---|---|---|
| 4 W for 24 hours each day | 2.88 kWh | $0.58 |
| 20 W for 8 hours each day | 4.8 kWh | $0.96 |
| 65 W for 8 hours each day | 15.6 kWh | $3.12 |
The eight-hour examples exclude the remaining 16 hours. Add sleep, idle or powered-off consumption separately if the machine remains connected. For a changing workload, calculate each period separately or measure the energy used over several representative days.
Measure the whole setup when that is what you pay for
A display, powered dock, external drives and speakers can change the total. A plug-in energy meter at the relevant outlet or power strip can measure the setup you actually use. Distinguish a momentary watt reading from accumulated kWh and avoid extrapolating a brief heavy-load reading to an entire month.
For an always-on setup, account for network and storage equipment too. Our router power-use guide uses the same energy calculation, while the NAS setup guide explains a separate kind of home-storage system whose disks and hardware need their own measurement.
Reduce consumption without assuming a fixed saving
Use appropriate display-off and sleep settings, close unnecessary background workloads and switch off accessories when practical. Decide what must remain available for remote access or background work. The useful comparison is the measured energy needed for your task, not whether a computer uses less power than an arbitrarily chosen light bulb.
Frequently asked questions
Does the Mac mini M4 use 4 W in sleep?
The 4 W figure cited here is Apple’s idle measurement for the specified M4 configuration. It should not be relabelled as a sleep measurement.
Will it draw 65 W all the time?
No. That is the published maximum-load result for a tested configuration. Actual consumption changes with workload and connected equipment.
How much does it cost to run all month?
Multiply measured average watts by operating hours, divide by 1,000, then apply your tariff. Add the energy used during other power states and by accessories if relevant.
Are M4 and M4 Pro figures interchangeable?
No. Apple lists different tested configurations and results. Match the chip and configuration when reading the table.