# 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.