What is the simplest way to calculate calories needed to lose weight?

I’m looking for the absolute simplest way to calculate how many calories per day an individual should consume in order to maintain or lose weight. I know a variety of factors are usually considered to calculate calorie requirements including current weight, age, gender, activity level, weight, height, desired number of pounds to lose and at what rate. However, I’m looking for a very simple way of calculating total calories needed to maintain or lose weight. I know there are online calorie calculators, but I’m not interested in those. I’m interested in simple calculation, if such a thing exists, that would allow an individual to quickly calculate this using a pen and paper or a handheld calculator. Any ideas?