money to carry for 2 weeks, family of 3

My husband, 1.5 year old son and I will be in Japan for two weeks. The first week will be for touring (Kyoto, Hiroshima, Osaka, Nagoya, Tokyo) and the second week will be with family in Shizuoka. We've already purchased plane tickets, JR rail pass (for the first week), and airBNBs. How much money do you recommend we carry with us? And also, how much money do you think we will spend? We are lower budget travelers and don't plan on buying too many souvenirs (we travel to Japan every few years).

This is our first time traveling as 3, so if you have any advice or experience we would really appreciate it! Thanks in advance.

I would recommend you take about as much as you have on previous visits when there were two of you, but a third again as much.

An alternative, if you have a bank ATM card, is to stop at a 7-11 and withdraw cash when you are running low. Let you bank know in advance that you will be travelling.

http://www.japan-guide.com/e/e2196.html