Gold Lot Blending Calculator

Blend two gold lots and calculate the resulting weighted purity, or solve how much of the second lot is required to reach a target purity.

Total Weight
Fine Gold
Blend Purity
Blend Karat

Gold Lot Blending Formula

Blended Purity = (Weight A × Purity A + Weight B × Purity B) ÷ (Weight A + Weight B)

For a target:
x = Weight A × (Target − Purity A) ÷ (Purity B − Target)

The target-weight solution works only when the target purity lies mathematically between the known and second-lot purities.

Why Blending Uses Fine-Gold Mass

Purity is a concentration, so the correct approach is to calculate the fine-gold amount contributed by each lot and divide the combined fine gold by total weight.

A mathematical blend does not replace physical assay or a metallurgical quality-control process.

Frequently Asked Questions

Can I blend a lower-purity lot with a higher-purity lot?

Yes. That is the basic use case for the target-purity mode.

What if both lots have the same purity?

The blended purity remains the same regardless of the weights.

What if the target is outside the two lot purities?

A solution is not physically possible using only those two materials.

Related Gold Tools

Gold Batch Average Purity CalculatorCalculate weighted purity across many lots.Gold Alloy Metal Requirement CalculatorCalculate target batch metal needs.Gold Alloy Recalculation ToolRecalculate changed batches.Gold Batch Value CalculatorValue blended material.