Model
Microfridge 3.1MF7R
Rank #46 means 45 of the 1,000 refrigerator models we track cost less to run each year; the 23rd efficiency percentile means it uses less energy for its size than 23% of those models.
What does the Microfridge 3.1MF7R cost to run per year?
Do the math and the Microfridge 3.1MF7R's $36/yr running cost puts it at rank #46 of 1,000, among the least expensive refrigerator models we track to keep running. It uses 46% less energy than the U.S. federal standard model in its class, which would cost about $66/yr to run, a saving of roughly $30 a year. Size-adjusted, this model trails most of its class on efficiency, ahead of just 23% of refrigerator models we track. This class has no published efficiency-factor figure beyond annual kWh itself, so at 3.1 cu ft (the class spans 1.2 to 31.7), size is the clearest lever we can point to for this model's running cost.
Immediately around it on the leaderboard, the Frigidaire EFR376-B-CORAL at $36/yr runs a little cheaper and the Frigidaire EFR331-B-BLACK at $37/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A refrigerator typically stays in service for somewhere around 12 years; over that span, the Microfridge 3.1MF7R's $36/yr adds up to roughly $432 in electricity alone, before purchase price or repairs.
By the numbers
The Microfridge 3.1MF7R normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $36/yr, here is what the Microfridge 3.1MF7R adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Microfridge 3.1MF7R costs about $360. That is roughly $300 less than a standard model in its class, which would run closer to $660 over the same ten years.
How the Microfridge 3.1MF7R compares
The refrigerator class we track runs from $8 to $149 a year. At $36/yr, it runs about $28 a year cheaper than the class median of $64, and it is about $28 a year more than the cheapest refrigerator to run at $8. Against the US federal standard model for its class at about $66/yr, the Microfridge 3.1MF7R uses 46% less energy.
What drives its running cost
At 3.1 cu ft, the Microfridge 3.1MF7R is a small refrigerator for its class, which spans 1.2 to 31.7 cu ft with a median of 12.6 cu ft, at the small end of the class, capacity itself is doing a lot of the work to keep that figure down, separate from how efficient the unit actually is.
- Interior volume. More cubic feet of cold air to maintain generally means a bigger compressor and a higher running-cost figure, even among efficient models.
- Counter depth vs standard depth. Standard-depth models generally offer more interior volume per unit of width than counter-depth models, a tradeoff between built-in looks and cubic feet.
- Compressor technology. How a compressor cycles, full on/off versus a variable-speed inverter design, is one of the biggest hidden differences behind two fridges with similar cubic feet but different running costs.
- Placement and ventilation. Ventilation clearance around the back and top matters more than most owners expect; a fridge starved of airflow runs its compressor longer to hold the same temperature.
Common questions
Is the Microfridge 3.1MF7R cheap to run?
Yes. Its $36/yr running cost puts it at rank #46 of 1,000, below what most refrigerator models we track cost to run.
How much does the Microfridge 3.1MF7R cost per month?
About $3.02 a month, which is the $36 annual estimate spread across twelve months at the US average rate of $0.1856/kWh. Your own bill scales with your local electricity rate and how heavily you use it.
How is this running-cost figure calculated?
The formula is annual kWh times price per kWh: 195 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $36 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Microfridge 3.1MF7R for its size?
23rd percentile once size is factored in. That means its size-adjusted efficiency is not the main reason for the running-cost figure above; its capacity plays a large role too.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 45 | Frigidaire EFR376-B-CORAL3.2 cu ft | $36 |
| 44 | Marvel MLRE*15-SS01A2.7 cu ft | $36 |
| 43 | Marvel MPWC415-SS31A2.7 cu ft | $35 |
| 42 | Danby DAG016A5BDH1.5 cu ft | $35 |
| 41 | Gaggenau RVW46777014 cu ft | $34 |
Source
ES_0031682_3.1MF7R_03012018110822_70170417View certified refrigerator listingsENERGY STAR data as of July 2026Microfridge and 3.1MF7R are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.