That’s not enough. You should probably be eating 1500-1700 calories per day. It is unhealthy to drop below 1200 per day. Try downloading an app like myfitnesspal and it will help you calculate how many calories to eat to reach your goal weight.
Calculations are ok but depending on your personal situation they may be very inaccurate grossly underestimating or over estimating your caloric requirements. This is because your metabolism is based on many factors, your activity level, your muscle mass etc. if you want to be super accurate use myfitnesspal to track your food for 2 weeks and take daily weights and weekly averages. You can then see if you are at maintenance or gaining or losing and also how fast so you can decide how to adjust accordingly. I like doing this because calculators always tell me to eat very little calories since I am a petite woman. When I track myself I get to eat more even with losing weight. Or if you want to do it faster use a calculator and track daily weights and take a weekly average and then make adjustments. But ya, I think those calculators are not designed for us petites.