https://www.aish.com/atr/Kiddush-How-Much-Wine.html

Kiddush – How Much Wine

I own two very nice Kiddush cups – I believe both were wedding presents. One happens to be quite large and the other fairly small. Is there a minimum or maximum size a cup must be? Also, when I use the large one, I tend to take only a few sips after Kiddush and leave most of its contents for the meal. Do I have to drink the entire cup? (I wouldn’t last very long in the meal if I did.) :-)

The Aish Rabbi Replies:

There is no maximum size for a Kiddush cup. The minimum size is clearly stated. A Kiddush cup must hold what’s known as a revi'it (literally, “a quarter”) – 1/4 of a “log” (Shulchan Aruch 472:9). How big is a revi'it? The Talmud (Pesachim 109a) measures it in terms of thumb widths – as the equivalent of a cube of dimensions 2x2x2.7 “fingers.” Elsewhere a log is defined as the volume of 6 eggs, making a revi'it 1.5 eggs.

Needless to say, there is much discussion in the more recent commentators exactly what these measurements mean in modern units. They note in particular that the two measures hardly square: Either our thumbs are somewhat larger than they were in Talmudic times or our eggs are smaller. (The former is actually much more likely.) As a result, opinions vary drastically – anywhere from under 3 ounces to over 5.

What should one do practically? There is another relevant distinction. On Friday night there is a Torah obligation to recite Kiddush, based on the verse “Remember the Sabbath day to sanctify it” (Exodus 20:8). By contrast, the Kiddush of Shabbat day is a rabbinical obligation – as a way of lending importance to the meal.

Thus, for the Friday night Torah obligation, one should be more meticulous and use a larger measure, based on the thumb measurements. A common practice is to follow the measurements made by one of the great rabbis of 20th century America, Rabbi Moshe Feinstein, who measured a revi'it as 4.42 ounces (130.7 ml). Others are more stringent to follow one of the past leading Israeli rabbis, the Chazon Ish, and to drink 150 ml = 5.07 oz.

On Shabbat day smaller measurements based on the volume of eggs is sufficient. The most accepted opinion for this (R. Chaim Noeh) is 86 ml, which is a bit over 2.9 oz.

Now how much of the cup should you drink? That is actually a separate question which I dealt with recently. Please see here for the response.

I should also mention that the cup should be filled completely even if it holds much more than the prescribed amount and more than you intend to drink (Rema 183:2).

More Questions


Due to limited resources, the Ask the Rabbi service is intended for Jews of little background with nowhere else to turn. People with questions in Jewish law should consult their local rabbi. For genealogy questions try JewishGen.org. Note also that this is not a homework service!

Ask the Aish Rabbi a Question

Receive the Aish.com Daily Features Email

Sign up to our Daily Email Newsletter.

Our privacy policy