According to Alan Borushek's Diet Manual For Successful Weight Control, "Theoretically, a loss of 1 kilogram of fatty tissue per week, requires a deficit of almost 8,000 calories (32,000 kj) per week or around 1,000 calories (4,000 kj) per day." He also said that this in practice will vary due to individual viables.
One kilo a week is good and the recommended amount. As one who did it too quick I know that any faster and you really stress your body. After a "good" result my voice would get very thin sounding. Other side issues are dizziness, tireness, loose skin (too rapid loss and your skin looks like a deflated balloon), irritablity, muscle wastage and you lose weight unevenly over your body.
Don't be too much in a hurry (I know...we all want it yesterday). Get the basics right and make it a lifestyle so that it will be a permanent loss.
You are doing well. I know it seems a long way before you reach your goal but every journey starts with one step. Don't sabotage yourself with too high expectations too quickly. Wishing you a successful journey.
Now: keeping it off for life!