CLICK ME =]

i've been looking through some posts and was hoping that you could help me slove this equation once and for all. im sorry if this seems a little repetitive to some.  

stats:

height: 154 cm
98lbs (looking to maintain)

ok here goes:

using the Harrison Bededict Formula my BMR is calculated at 1,283. this is the number i need just to keep my body ticking over right? 

ok so assuming everyone is sedentary in their day to to living i calculate 1,283 and muliplied it by 1.2 (sedentary)

example: 1,283 calories x 0.20 = 256 calories

i then added together my BMR and calories burned by my activity level which then gives me 1,539.

i also factored in calories used during the digestion of food which is normaly 10% for the general population right?

example: 1,539 x 0.10 = 154 calories + 1,539 calories = 1,693 calories. 

so therefore i burn an average of 1,693 calories everyday to support my bodys most basic needs, activity level and digestion of food.. right?

(please tell me if this is right)

ok now lets say that im other than sedentary in my normal day to day living and do other activities which burns about 300 - 500 calories. would i then just need to add these (or some) of the calories burned through my activity ontop of my normal calorie expediture of (1,693) to maintain my current weight?

(taking into account calories burned through activity will vary each day but if ive got this sussed i can almost figure out the rest!)

- id rather add my acitvity calories manually to get a more accurate result, which is ok right? 

if anyone would be so kind and tell me if this seems about right i'd be very much grateful =]

i was also wondering if anyone could post me the correct formula for a calorie deficit. not that i want one but what would you say a safe deficit would be just to help maintain?

I think you've got everything right.... although I haven't heard of factoring in the digestion bit... I always thought the Harris Benedict already did that.

i dont know  i just thought it was one of the three elements used to help determin your total calorie need

• energy for basic body processes (BMR) 70%
  your resting metabolic rate (the amount of energy needed to enable the body to functon over 24-hour period)
  
• digestion of food (thermogenic rate) 10%
  the amount of energy used in digesting and processing the food (known as the thermic effect of food)
   
• physical activity (activity metabolic rate) 20% the amount of calories you expend during activity.

if you google 'the thermic effect of food' it tells you all about it. but i wasnt sure myself wether or not that the thermic effect of food is already included in the equation?

some advice please folks??