Are there any food storage guidelines or calculators online besides the one used by the LDS?

My new hobby is prepping and I’m having some issues with finding different guidelines and progress trackers for storing food. No matter where I look and how long I say I want to save for, online sites always say 14 gallons. I know it’s about 1 gallon per person per day just to drink. They all seem to be copies of each other and I was wondering if there are any other ones that allow for different things. I know that I should only include things that I will actually eat and stuff, but I was wondering if there is anything that I’m missing.