what is the standard height of a picnic bench
(picnic table image by Horticulture from Fotolia.com) Standard-size A-frames use five to seven lengths of timber for the table top and two to three lengths for the seats. A standard table top height is about 30 inches while the height of the seat top should be about 16-18 inches. Aploon/iStock/Getty Images. Childrenâs picnic tables are made to a smaller scale than regular A-frame tables. They usually feature four lengths of timber for the table top and two lengths for the seats.