I wasn't sure about this either so I did some digging myself. And wonderwiper is correct. You can claim any amount as long as you can prove it is reasonable. I don't separate my receipts for groceries as the kids eat everything that we eat (for e.g our lunches are last nights leftovers). If anything I actually think they eat more $ wise because I serve TONS of fruits, veggies, and cheese (which we all know it's very expensive to eat healthy). I am licensed and only started last July so I had all my biweekly numbers of who was here FT and before/afterschool. So I just added my FT and BF/AS kids and days and just charged $6 ($1.50 for 2 snacks and $3 for meals) for FT and $2 for BF/AS (afterschool kids eat more than the little ones). It worked out to be just over 50% of my grocery receipt total (I have 3 FT and 2 BF/AS kids, plus my own 2 yr old, my husband and myself).

I've also seen people charging up to $10+ for a full day because they are buying all organic and more expensive food as well. For me, this year I will just add up my totals monthly so that it's not so much adding at the end of the year. Whatever method you choose (whether it's a percentage of your groceries at year end or a daily rate) just be consistent and use it every year and be able to justify it in the case that you may be audited.

ugh....taxes suck! But they feel so good when it's done
Good Luck!!