question about calculating carat weight

[nycguy]

is there some kind of program or formula that you can input height, width, depth, pav angl, girdle, crown angle, cutlet, and get the carat weight?

thanks!

 

[DiamondExpert]

A general formula for SRB's (Standard Round Brilliants) with 58-60% depth and med girdle is: Ct. = height(mm)X diameter(mm)2 X 0.0061. Variations of depth and/or girdle require a 1-5% fudge factor.

For the fancy shapes things are a bit more complicated and the formulae are varied depending upon the Length:Width ratios.

 

[Garry H (Cut Nut)]

For most smaller round brilliants you can use lxwxd x .00625.

The most accurate system is DiamCalc for all shapes and variations etc.

 

[alice123]

great, thats helpful. does that formula only really hold true for very well cut stones or is it consistently accurate regardless of angle variation etc?
thanks!

 

[Garry H (Cut Nut)]

It is reasonable for a wide range, it includes a factor for average girdles which are thicker than on well cut stones.

 

[DancinGirl]

Hey I never knew this little trick! Very cool! I just tried mine and it came out to be a 1.10 - and mine is a 1.07... not too bad of a difference there!

 

[Garry H (Cut Nut)]

Yes DG

It will give a higher weight for most stones over 1/2 ct.