The calculation
Liquid product required in millilitres = water per feed in litres × number of feeds × dose in ml/L. For a full run, calculate each stage separately when any of those inputs changes, then add the totals.
One transparent example
At a hypothetical dose of 1 ml/L, 20 litres per feed for 12 feeds uses 240 ml of product. This example explains the arithmetic; it is not a Crazy Hills dose recommendation.
Separate irrigation from feeding
Count only the applications that include the product. Do not use total irrigations if some are water-only. Use the volume for the whole area being calculated, not per plant unless you also account for plant count.
Commercial quantities
For a commercial plan, send the stage lengths, daily volumes and feeding frequency. Larger formats can change the order plan. We can discuss quantities and availability using the same assumptions you use in the grow.
Plan a commercial order