According to the NIV Bible in 1 Kings 10:13-15 and 2 Chronicles 9:12-14, King Solomon received 666 talents (t) of gold per year as salary. He also received other moneys from various merchants, traders and surrounding governments.
If we just look at his annual salary, one talent of gold is approximately equal to 34.5 kg. One kilogram converts to 1109 troy ounces (ozt). At current market prices (August 2012), one troy ounce of gold trades for about $1,648 U.S. Dollars (USD). Multiplying $1,648 x 1109ozt x 666t = 1,217,202,912 or roughly 1.2 Billion dollars per year. Keep in mind this was only his annual salary, not including any 'bonuses' or investments.
King Solomon ruled for 40 years so that's like 4.8 Trillion during his lifetime. If you take into account all the extra income he surely would have received, I'd guess his net worth to be somewhere in the neighborhood of 10 Trillions.
Compiled by Max Shimba