Weight by volume
In the ideal volume-additive model, 10 L at 20% plus 10 L at 80% produces 20 L at 50%. Unequal volumes require a weighted average. This is mathematics, not a Probably Stolen test result.
The target has a hard limit
To raise a blend to a higher target, the added water must be purer than that target. If it is only as pure as the target, a finite addition approaches the target without reaching it.
Compare equal outcomes
Save multiple blends with the same target and comparable volumes. Include the cost of the additional water. A cheap starting mixture may be expensive to bring up to the target.
Know the model boundary
This calculator does not model Probably Stolen contaminants, filters, chemical reactions or quality thresholds. Numerical purity bands are explanatory ranges defined by this site.
Editorial tool guide · Updated October 28, 2026. Arithmetic examples are not game observations.