SGRs
For EMZWs between 70 and 80 tonnes, and a cruise level between FL290 and FL350,
Mach No: SAR (nil wind)
M 0.84 10.3
M 0.82 10.0
M 0.80 9.5
M 0.79 9.5
LRC 9.2
If your EMZW is not between 70 and 80 tonnes,
If over 80 tonnes, add 0.5
If under 70 tonnes, subtract 0.5
If your cruise level is outside FL290-FL350, add 1.0
For a headwind, add 0.02 per knot of wind.
For a tailwind, subtract 0.02 per knot of wind.
The resulting number will be pretty darn close to your SGR.