Calculate the size and price of Common Gemstones


These interactive pages allow you to calculate your relative carat size using your ruler to measure in millimeters or tenths of an inch as well as cut, shape and height. It also applies specific gravity to estimate volume before supplying the resulting carat weight.

Then with the carat size and the gemstone rating a price formula is enacted to give you an indication of the possible value of your gem.

The cost refers to an average gemstone without flaws. It reflects average color purity, brightness and medium fire. Prices are neither retail or wholesale. They approximate average international trading prices for cut stones as pertaining to our market experience (circa 2012). There are restrictions regarding small or very large carat sizes as it is impossible to make such estimations without misleading generalizations. It also takes into account the gemstones availability and its popular demand.

Look at our section on gem descriptions and ratings as evidenced by our market experience up to 2012.