# How much should Rosho Verubo be for Succah measurements?

The Gemmorah (Succah 3 and Mishna on 28) states that the requirements for a Succah are that a person can fit it "ראשו ורובו" - the head and most of the body.

IIRC the average body is 3 Amot (18 Tfochim)Gemorrah elsewhere and the head is about half Ama (3 Tfochim) for a total of 21 Tfochim (5'9 or 175cm). So, Rosho (3 Tf.) + most of his body (10 Tf) would equal 13 Tfochim.

We know that they ate laying horizontally on beds, otherwise, if one sits or stands vertically, IMHO, Rosho AND Rubo is meaningless, as the head is above the body.

The Halachah ruled is 7x7 Tfochim.

I see a contradiction here, how can it be reconciled?

• I always understood רובו to mean most of the torso. Commented Sep 12, 2019 at 12:42
• @DonielF Hm, great, I think that counts as an answer! Maybe somebody will find a source. Commented Sep 12, 2019 at 12:49
• "average body is 3 Amot" in which dimension? Most of us aren't spherical Commented Sep 12, 2019 at 12:54
• The average body is 3x1x1, which is how we get that a miqvah needs to be 40 se'ah of water. 3 cubic amos. 10 x 7 x 7 techaim would be 2-29/108 cubic amos. Which is well more than rov. But then, it's not rov of the head, it's ALL of the head and rov of everything else. I don't think you need to exclude arms and legs for this to work; you just have to use volume, not linear measurements. Commented Sep 12, 2019 at 17:06
• @DoubleAA akready pointed out that linear measurements don't fit the problem. Commented Sep 12, 2019 at 17:06