Follow The Golden Rule
Wages should be 45% or less of the revenue the driver generates. Use this calculator to quickly figure out a profitable workload to dispatch.
Use the Daily Driver Wage slider to enter what you pay a driver daily.
Use the Revenue Per Stop slider to indicate what your revenue per stop is.
This is the number of stops needed to dispatch in order to make the driver wage be 45% of the revenue they generate.
Keep in mind this is a rough (but fairly accurate) estimation to figure out your most profitable dispatch.