score:9
I'm not sure how you'd go about approximating the percentage of products with English, but I can suggest an easy workaround: the camera mode of Google Translate, formerly known as Word Lens.
This is available for Android and Apple mobile phones, costs nothing and works offline as well if you download the language pack in advance.
(Obligatory disclaimer: I work at Google, but have nothing to do with Translate, except as a satisfied user.)
Also, FWIW, I've done a lot of grocery shopping in countries where I don't speak/read the local language, and rarely if ever can I remember being seriously inconvenienced: you may not know what everything is, but it's usually straightforward to find a specific thing you're looking for. Most products are obvious in any language, since the packaging is either partly transparent or contains pictures of the contents, and many brands for things that may not be (detergent, shampoo, toothpaste, etc) are global.
Upvote:3
I don't think such a list exists as such.
Also this will be very specific to the area / country you are travelling to.
My impression is that there are certain everyday items that you want to have during your travels that make you feel more confortable.
Make a list of these items:
For each item collect the package wraping
Make a list of the countries / Cities you are going to visit
Compile this information into a A5 binder that contains plastic* envelopes
* I know and understand that plastic is a no, no - but on a windy, rainy day more practical
The best weapons against the language barrier are pictures
Properly prepared, just pointing to the picture and translated name of product and shop type will probably get your very far, very swiftly.