How Can I Precisely Calculate Exhaust Velocity?

I'm writing an advanced auto-pilot script for my Birgo rocket, and I need the exhaust velocity to calculate impulsive dV given a mass of fuel burned. Using the 'FUNK' expression, I've been able to collect information on:
- Maximum Thrust
- Maximum Mass-flow Rate
- Chamber Pressure
- Nozzle Exit Area
- Nozzle Expansion Ratio
However, for the life of me, I can't figure out how to calculate my exhaust velocity. I tried hard coding the values as seen in the editor, but they aren't accurate enough (only three significant figures). Is there any way to obtain an accurate exhaust velocity? (or some way to reformulate the Ideal Rocket Equation [dV = Ve * ln(Mf/Me)] in terms that are precisely obtainable. ISP not being one of those)