Measure Actual Melting Loss
Use measured weights before and after processing.
Weight loss alone does not identify what material was lost. Non-gold content, residue and other material changes need to be evaluated separately.
Gold Melting Loss Formula
Loss % = Weight Loss ÷ Starting Weight × 100
Yield % = Final Weight ÷ Starting Weight × 100
These formulas allow measured batches to be compared consistently regardless of the absolute batch size.
Why Measured Weight Matters
An expected loss percentage is useful for planning, but an actual loss figure should be based on measured weights. This makes the result specific to the material batch and process being evaluated.
Expected Loss Compared With Actual Loss
The optional expected-loss field calculates the theoretical final weight based on that assumption. The variance then shows whether your measured final weight is above or below that expectation.
Worked Example
Final Weight = 99.2 g
Loss = 0.8 g
Loss Percentage = 0.8%
Yield = 99.2%
Weight Loss Does Not Automatically Mean Gold Loss
A batch can contain other metals, residues or material that is removed during processing. Therefore, the difference between two scale readings does not by itself prove that the same mass of fine gold was lost.
Where precious-metal accounting is important, combine accurate weighing with appropriate composition or assay information.
Frequently Asked Questions
How is gold melting loss calculated?
Subtract the final measured weight from the starting weight, then divide the difference by starting weight.
What is a normal gold melting loss percentage?
There is no single universal percentage for every material and process.
Can weight loss prove that gold was lost?
No. Other materials can account for some or all of the weight difference.
Can I compare actual loss with expected loss?
Yes. Enter an expected rate to calculate expected final weight and variance.
Does melting loss change karat?
Weight loss alone does not establish a change in karat.