What is the correct size for a Kiddush cup?
Posted by Moshe Friedman on
The requirement of drinking four cups of wine is rabbinic in nature and the minimal measurement required for the four cups is a rivi’is for each cup. There are variances amongst contemporary halachic authorities as far as how this measurement should be calculated as well.
The minimal size recommended by Rav Chaim Noeh is approximately 3 ounces , whereas 3.3 fluid ounces is the proper amount according to Rabbi Moshe Feinstein, and 5.3 fluid ounces according to Chazon Ish. It should also be noted that if one’s cup holds greater than a rivi’is, one should try to drink the entire cup or at least most of it .