Wouldnt know how to add those annoying swipe ups even if I wanted too haha. Your best way to calculate daily cals is to use tools like iifym or similar. But my recommendation (I'm a PT) start higher (even 2000 is not a bad place to start but this all depends on your natural daily expenditure and not just exercise, ie a desk job burns less naturally daily then a cleaner etc) and work back wards. Stick at first set of cals for 2 to 4 weeks (be super strict with tracking initially but dont worry it wont last forever) if you stay the same or gain then you can drop. I advise no more then 50 cals a day drop at a time. So few weeks at 1950 then 1900 etc, once you find a set you lose at stay at that untill.you maintain for a few weeks. Then drop again. Eventually you will hit either your weight or maintenance
My second advise is dont pick a weight on the scale number as your ultimate goal, just because you want to be 9 stone does not mean your body wants to be. Having a higher muscle mass can cause your over all.body weight to be higher then that goal weight even if your body looks amazing. You might be cracking at 11 stone because you have a higher muscle mass and lower body fat (just look up female cross fit athletes and their body weights for example).
But please dont drop low immediately or too low ok general
Hope this helps