# Borrowing rates

\
The pre-kink multiplier of a pool is $$M\_{x}$$ and post-kink is $$M\_{y}$$. Additionally included (but set at 0 for all pools initially) is a fixed flat interest rate $$F$$ is managed through governance. Borrower’s interest rates are calculated using this formula:

$$
BorrowRate\_{a} =\begin{cases}F + Pool\_{a}Util\* M\_{x}, if ,Pool Util  \leq Util\_{optimal}\F + Pool\_{a}Util\* M\_{y}, if ,Pool Util  > Util\_{optimal}\end{cases}
$$

 $$Util\_{optimal}$$is set at 80% to begin in both stable coin pools as well as variable asset value tokens.