Quoting from a reliable source, the Ark was made of acacia wood
overlaid with gold. Also, the depiction here is highly likely to
be wrong, especially since the rings are said to be on the feet!
It was 2.5 cubits long, 1.5 cubits wide and high. Above the
chest was the Mercy Seat, upon which were a pair of cherubim
shrouding the ark. There were four cast gold rings on the feet,
in which were placed gold-overlaid acacia carrying poles.
Converting from cubits to feet, using 18″ per cubit, the chest
portion of the Ark was 3.75′ (45″) by 2.25′ (27″) by 2.25′
(27″). For sake of argument, I am going to presume the boards
were 2″ thick. Acacia has a good density, at roughly 650kg per
m3, or about 40.6lbs per ft3, or about .373 oz per in3.
3.75*2.25*4 (if the Mercy Seat was actually gold overlay on
acacia) + 2.25*2.25*2 is a total of 43.875, or 43 7/8 ft2 of
acacia boards (the 4 sides, bottom, and mercy seat area). That
is a total of about 25 pounds of wood (rounding) for the Ark
proper. I am going to presume a 1/32″ l