Dining bench dimensions

I've finished a trestle dining room table for my daughter. It is 36x84. The table is white oak with mahogany accents. I have decided...pardon me, it has been decided for me that there needs to be two accompanying benches for this table. I will profile the seat for comfort, but how deep front to back should a seat bench for a table be? Also, should it be tipped forward or back for comfort. I have ordered some 7/4 mahogany for the bench seat. There will be no back on this so it is a true bench. Outside to outside the trestles are 63". Overall length will likely be around 70". Much obliged for any suggestions.

I did the plans for this table with benches awhile back. The seats are about 15 in. front to back. The planks have a shallow bevel toward the center line. I would do that or leave the seat flat.

The bench I built is 15” wide, flat. Never had an issue or complaint.

I looked at some dining benches in a furniture store last night. They ran 14" - 17" in depth. I thought the deeper ones were more comfortable to sit on, but I don't think there would be any need to go beyond 17". None of the ones I looked at had a contoured seat. I imagine that would add to comfort, but I don't think it's really necessary. None of the benches I saw had any tilt to the seat.

Mine are only 12" and they are plenty wide enough even for my butt! More important to me is how the benches are designed to slide almost all the way under the table. They are knee knockers.

Hopefully the decision for benches was made with full knowledge of how uncomfortable they can be. I would actually be in pain after eating a dinner meal with no back to rest against. Also issues with people moving about. If the person sitting in the middle has to get up during the meal, someone else is interrupted. I really dislike benches, despite the effort furniture companies use to make them look acceptable in glossy sales brochures.

The most recent one i built was 11.75" wide, honestly i don't see the need for much wider than that.

Benches are fine for a young family and kids. My folks (in their 70’s) however need a proper chair.