1 1/8 Inch Steel Cable Weight

Do you mean 1¹/₈ cable or one 1/8 cable? The post is unclear.

is this cable solid... if so the basic formula for figuring out weight ot solid round bar is dia * dia * 2.67 = weight per foot.

There are different types of steel cable, look at
http://www.package.nl/pdf/7_staaldraadindiverseuitv.pdf

it is a shame it is in Dutch language but look at diameter 28 mm on the
3rd page it is with rope core = 298 kg / 100 mtr suitable for a load of 46.7 tons
4th page it is with steelrope core = 328 kg/mtr suitable for a load of 55.8 tons

Peter

Wire rope 1-1/8" diameter 2.03 lbs/ft.

Depends upon the construction. 1-1/8" diameter 6 x 19 strand galvanized steel wire rope is 2.03 lbs per ft. That's a typical wire rope used for hoisting, lifting, etc. It's concentric stranded (6 x 19 strand wire bundles over a jute or similar flexible core).

In contrast, 1-1/8" diameter, 19 strand galvanized steel guy wire is also concentric stranded and consists of 19 x .161" diameter coated steel strands. Construction is 2 stranded layers (6/12 ) over a single steel core wire of the same diameter. Guy wire of that construction is 2.691 lbs per foot.

If you mean the mass of 1-1/8" steel, then the answer as some one gave would be a good reference. But if you mean "Weight", you should consider about your local gravity and air density. The best way is weighing a 100fts sample 30 times more, and take the mean value for a uncertainty estimate.