We bottle our fragrances by weight not volume as each fragrance has a different density. This helps us to be more precise and consistent and we also recommend makers do the same (weighing oils) to measure how much to put in the product for the same reason.Some oils are much heavier than others and that’s why some appear to be lower, however the advertised weight should be correct. If you would like to verify that you received the correct fill line, you may send an image to hello@midwestfragranceco.com or you can weigh it yourself to check!This information is listed on the website as well as we try to be as transparent as possible. We also include “care cards” in orders to answer questions like this for everyone. Please read over that for more helpful fragrance care recommendations and more info! Click here to see the care card.