For the food in your refrigerator to stay fresh for as long as possible—no ice crystals on the lettuce or bacteria breeding in warm spots—the refrigerator temperature should hover right around 37° F. In the freezer, a temperature of 0° F will keep foods thoroughly frozen.

Knowing that, the reasonable step would be to set your refrigerator to those temperatures. But the temperature controls on many refrigerators only allow you to choose from a series of numbers—say, from 1 to 5, with 1 being the coldest and 5 the warmest. Even when refrigerators have digital controls that allow you to set a specific refrigerator temperature, the settings aren’t always accurate. But the temperature-measuring equipment Consumer Reports uses in its tests is extremely precise, down to a fraction of a degree, so we can tell you exactly where to set your refrigerator temperature to achieve optimal freshness.

How Our Testing Works

When a new batch of refrigerators comes into our labs, we start by setting the ambient temperature in our climate-controlled chambers to 70° F, which simulates the conditions in most kitchens. Then we determine which temperature setting on each refrigerator will get the refrigerator temperature in the center of the unit to between 36° F and 38° F. We do the same thing in the freezer, figuring out how to get the freezer temperature to between -1° F and 1° F. 

Some refrigerators are spot-on. Temperatures inside the GE GFE26GSHSS French-door refrigerator, one of our highest-scoring models, stay right around 37° F mark in the fridge and 0° F in the freezer when it’s set to these temperatures. But other refrigerators are wide off the mark. With the LG LFXS32766S French-door refrigerator, for example, you need to set the refrigerator temperature to 40° F and the freezer to 2° F to achieve 37° F and 0° F conditions.  

It’s important to note that we don’t penalize refrigerators for inaccurate settings. The aforementioned LG, in fact, has a slightly higher overall score than the GE. Both models are superb at maintaining consistent temperatures once they reach the optimal level. The point is that you need to know how to get them to the 37° F and 0° F marks. And that’s why we now include this information in our refrigerator ratings charts, under Features & Specs. You’ll find the ideal temperature setting for refrigerators with digital controls, and the ideal numeric value for models with that type of thermostat.

What if your refrigerator isn’t one of our tested models? Your best bet is to buy a refrigerator thermometer, available online and at home centers for a few bucks, and conduct your own experiment. The thermometer won’t be as exact as the sensitive thermocouples we use in our refrigerator labs, but it should get you within a degree or so of the perfect refrigerator temperature to keep your food fresh, tasty, and safe for as long as possible.