Please provide more context! A ratio of 128 doesn't tell us anything about the yield of a product.

To calculate the yield, we need to know:

* What the ratio represents: Is it a ratio of ingredients, a ratio of input to output, or something else entirely?

* The units of measurement: Are we talking about gallons, liters, pounds, or something else?

For example, if the ratio 128 represents the amount of raw materials needed to produce one gallon of product, then the yield would be 1 gallon per 128 units of raw material.

Please provide more information about the ratio and what it represents.