# Stone Weight Estimation Formula

Posted June 16, 2014 by Esslinger Staff

#### This is a guide on how to estimate the approximate weight of a gemstone based on its **length to width ratio**.

**length to width ratio**

### Round

**Diamond:** Average diameter² x depth x 0.0061 x weight correction٭

**Color Stone:** Average diameter² x depth x S.G. x 0.0018 x weight correction*

### Oval

**Diamond:** Average diameter² x depth x 0.0062 x weight correction٭

**Colored Stone:** Average diameter² x depth x S.G. x 0.0020 x weight correction*

(use average length and width for diameter)

### Pear

**Diamond:** Length x width x depth x adjustment factor x weight correction٭

**Adjustment Factor**

Length to width Ratio |
Adjustment Factor |

1.25:1.00 | 0.00615 |

1.50:1.00 |
0.00600 |

1.66:1.00 |
0.00590 |

2.00:1.00 |
1.00575 |

**Colored Stone:** Length x width x depth x S.G. x 0.0018 x weight correction*

### Marquise

**Diamond:** Length x width x depth x adjustment factor x weight correction٭

**Adjustment Factor**

Length to width Ratio |
Adjustment Factor |

1.25:1.00 | 0.00565 |

2.00:1.00 |
0.00580 |

2.50:1.00 |
0.00585 |

3.00:1.00 |
1.00595 |

### Emerald Cut

**Diamond:** Length x width x depth x adjustment factor x weight correction*

**Adjustment Factor**

Length to width Ratio |
Adjustment Factor |

1.00:1.00 | 0.0080 |

1.50:1.00 |
0.0092 |

2.00:1.00 |
0.0100 |

2.50:1.00 |
0.0106 |

### Heart

**Diamond:** Length x width x depth x 0.0059 x weight correction٭

**Colored Stone:** Length x width x depth x S.G. x 0.0021 x weight correction*

### Triangle

**Diamond:** Length x width x depth x 0.0057 x weight correction٭

**Colored Stone:** Length x width x depth x S.G. x 0.0018 x weight correction*

### ٭ Weight Correction

**All Cuts:** Add between 3% and 8% depending on thickness of the girdle. A high or lumpy crown may require a correction of up to 10%.

**Oval, Pear, Marquise, Heart:** Add up to 10% for wide wings or high shoulders.

**Step Cuts:** Add up to 18% for pavilion bulge.