First, the formula. The alleged “tariff rate” from each trading partner is fully a function of trade aggregates, specifically, the deficit divided by US imports, with a minimum of 10 percent. No factors discussed by the administration in these documents or anywhere else (like tariffs, digital services taxes, value-added taxes, or monetary policy) play any role.
For example, Singapore is a relatively free-trade-oriented country, while Brazil makes considerably more use of tariffs and other trade manipulations. However, both end up with the 10 percent rate because of their goods trade balances with the US. By contrast, Vietnam, which exports a great deal to the US but has also worked to make its policies amenable to the US, gets no credit for the effort.
The US response is generally half the alleged rate from other countries, though in some cases it appears to round up an extra percentage point beyond a simple halving.