Cycling/fitness, How Many Calories?

[shadowx 0]

So, I have been on a diet since July time, excluding about 4 weeks around christmas, my diet involves just eating less calories and it has meant I have lost 6 stone going fro, 21 stone to now 15 stone (210lbs at 6ft 2" tall) This has just been by controlling calorie intake, sticking to 1500 calories a day trying not to get below or over that. I am a male so that is a loss of 1000 calories per day. So far so good, I have lost the weight and I have no ill effects, I am not tired nor ill and I dont look ill either so I am happy with my diet.Recently I have started cycling a lot both for fitness and for enjoyment, I simply like being outside! I have two routes I follow, mostly it is a 12 mile route on flat ground and my other route is 6 or 7 miles along mostly flats with the odd hill thrown in. My app on my phone configured with my weight and GPS says I burn around 8-900 calories on my 12 mile ride, so what sort of calorie intake should I be aiming at? My goals are to bulk up muscle a bit and add tone as well as increase fitness and steadily loose a little more weight. The obvious choice is to just eat 8-900 calories extra but would that be correct?I am also a vegetarian so my protien and what not comes from artificial meat like Quorn and Tofu or Soya.Any ideas?