The bag says a certain number of cups, how do I convert that to grams?

Some kibbles are small and dense, packing more weight into a cup, while others are larger and more airy, holding less weight in the same volume, and this difference can be 30g or more per cup between two ordinary brands.

A generic online conversion figure is only ever an approximation and can be noticeably off for your specific product.

Fill the same measuring cup you would normally use to the level the bag describes, then weigh it, ideally averaging two or three fills for consistency.

Multiply that gram weight by the number of cups listed on the bag for your dog's weight to get the total daily grams, then double check this against a resting energy calculation for a sanity check.

Once you know the gram equivalent, you can weigh future portions directly rather than measuring cups each time, which tends to be faster and more consistent day to day.

If the bag's cup based recommendation and your own resting energy calculation differ significantly, lean toward the calculated figure and monitor body condition, since printed charts are often generous averages. Keep both numbers written down somewhere handy in case you want to double check your working later or compare against a future food switch, since both figures are useful reference points once you have gone to the trouble of working them out.