Daily babysitting rates?

What do you think it is decent rate for babysitting and how do you decide on what to charge? Ive watched kids throughout the past few years From my home and I always just gave a price I thought was fair or worth it to me or worked out a set weekly rate with family. I have 4 kids of my own and my older 3 will be in school most days. Inwill have my 1 year old and will be taking in a 5 month old and a 3 year old an average of 10 hours a day. I will also provide meals. The 3 year old I will not have 2 days a week bc she’ll be in school. I live in ny state in a small town where a lot of families cant afford to pay over $10 please let me know any of your thoughts and suggestions.