Bento boxes come in a tremendous variety of sizes, styles, and designs. Shopping for a box can be frustrating, especially when you don’t have a good idea of what you are looking for. I wrote this guide to help you narrow down your options before you go shopping.
(Looking for a recommendation for where to buy your bento box? Check out my handy shopping list.)
How Big Should It Be?
When you’re shopping for bento boxes, the first thing you’ll want to know is just how large you want your bento box to be. Bento boxes are measured in milliliters, and the general rule of thumb is that when food is packed in bento-style, 1ml will hold roughly 1 calorie worth of food. The easiest thing to do, then, is to figure out how many calories you want to eat for lunch, and buy a bento box exactly that large.
Be warned, however, that even the largest bento boxes look impossibly small to American eyes. They certainly did to mine. I originally bought 900ml boxes for the guys, but after a couple of weeks of use, they admitted that the boxes held too much food for them to eat at one sitting. These days they usually eat some of their bento for lunch, and snack on the rest over the course of the day.
Our next purchase was a set of 650ml boxes, which are just about perfect for us. My biggest piece of advice here is to stick to the calorie limit you think you ought to. Bento boxes will hold a lot more food than you think.
Microwave and Dishwasher Safe?
Although many of the bento boxes I’ve seen have been microwave and dishwasher safe (with the notable exception of the inner lids), enough of them aren’t that I’d caution you to check on this if it’s important to you.
With regards to microwaving, especially, you may want to keep in mind that most bentos are packed with the intention of eating the food at room temperature. This will require you to practice some mindfulness about food safety measures while you’re packing the boxes. I would also encourage you to season the food more heavily than usual, since food served cold or at room temperature has its flavors somewhat muted when compared with hot.
If a microwave is not available and you feel that it is essential to have a hot lunch every day, there are a number of options available in the way of thermal bento boxes.
Is It Watertight?
Most bento boxes are not watertight. You will want to be careful about packing wetter foods. I have found that one of my boxes is far better than the other for holding things like curry, but it is still not watertight enough for me to pack soup. Whenever I pack something wet like curry or a particularly wet pasta sauce, I warn the guys beforehand to be careful in carrying their bentos. That way they don’t get carelessly tossed into a laptop bag with disastrous results.