Be sure to have the correct weight. That might be the hardest part to figure without a small weight scale. Using a digital scale is probably the easiest way. 14 karat and 10 karat are pretty common when it comes to jewelry. Higher carats are more pure form of gold and will cost more money. If gold doesn't have a karat stamp its a good idea to go get it tested with a professional jeweler.
Gold prices fluctuate day to day. Most gold calculators have the daily gold rate built in. Some dont. So be sure the calculator updates automatically or go check what gold is selling for today before making a calculation.
The value of 14k gold depends on the market. Gold is measured by the Troy Ounce. This means that an ounce of gold can be worth around $1,100. But, if the market is in a recession the gold prices may drop.
Gold is measured by grams. The worth depends on how much gold you have and that the current price of a gold of gram is worth. This price constantly fluctuates. You can find more information here: http://gold.yabz.com/jewelry.htm