The only subjective data you enter into my calculator is activity hours. The Healthy Body Calculator® is based on current nutrition practice for assessing people’s weight and calorie needs. Actually, it is very accurate, but I don’t use a single multiplier. There are formulas that use a single multiplier for quick field estimates of calorie needs that range from 12 – 15+ calories per pound of body weight for healthy individuals.
Unfortunately, most people underestimate how much they eat as they don’t keep food and drink records which should be analyzed for calories and nutrients. Another important factor is the amount and intensity of exercise & fitness you get each day, but since you are sedentary, this wouldn’t be a factor. Better get moving as people who burn more through exercise, can eat more calories.