"Breakaway thrust" will vary with the aircraft type, the temperature of the grease in the wheel bearings, the tire inflation, the aircraft weight, the gradient of the taxiway or ramp/apron, wind, engine efficiency, taxiway surface, tire condition, temperature, and other such factors. Each is a variable, and each will affect aircraft operating under identical conditions, differently. Accordingly, you're not going to be able to put together a formula which accomplishes what you want.