You’re assuming that 6.22tn is all from domestically produced base materials and therefore the correct denominator component for that 18.6bn number. I cannot find what base materials imports compose that number but I bet you it adds quite a few hundred basis points to your equality.

Just look at origin of packaging for most food items. They are often not the US, and shipping to/from external counties of origin isn’t economical.

This might be a relevant calculation if the price rise will lead to increased production, allowing for just as much food to be produced as before (or maybe just slightly less), at an only slightly higher price. But it's not at all clear that that is the situation. It may turn out that there is no way to make up the shortage. If so, there will be a reduction in the amount of food produced. Depending on the magnitude of the reduction, you may die.

You're assuming that it's simply a component that will be passed on in the price, rather than affecting the supply/demand levels, or being multiplied by the margins of various intermediaries?

> Total retail and food services sales in the U.S. $6.22tn

Every dollar that passes through every restaurant or grocery store, plus all commercial catering? Is some of that double-counting food processing as well?

> Total retail and food services sales in the U.S. $6.22tn

I cannot bring myself to believe that that number means what it sounds like it means, because the total GDP of the USA is $24.8 trillion and that makes food 25% of the American economy, which seems implausibly high.

supply chain doesn't work like this. This is a bit like saying, I cut off one root of the tree and there are million branches so it will survive.

Most of the times, retail has a profit margin of around 5-10% and restaurant is even worse with around 1% margin.

An increase in base price has a knock on effect that ripples through the entire system.