Weight Loss Forcast Calculator

Trying to lose weight for a special event?

This post will explain to you how to calculate your projected weight loss. Please keep in mind, this is your theoretical weight loss, and often times your body will act differently.I did, however, conduct an experiment testing this theory a few months ago, and found it to be surprisingly accurate. Check it out here.

The first thing you need to figure out is what you daily calorie burn is just from being alive, we’ll call this CO1. You can use many tools for this including online calculators and fitness trackers.

To give you a rough idea, a 6′, 90kg, 25yo man burns 2819 calories a day. A 5’4″, 80kg, 25yo woman burns 2153 calories a day. To calculate your daily burn, check out this site.

Next you need to determine how many calories per day you’ll burn doing exercise per day, we’ll call this CO2. You can calculate this at the same website above. If you are using a fitness tracker, like a Fitbit, make CO2 equal to 0. This is because your fitness tracker will track your daily burn as well as any exercise and roll it all into one.

And finally, you need to determine how many calories you’ll eat each day, we’ll call this CI. It is recommended never to eat less than 1200 calories per day.

The formula for your weight loss per week is:

Weight Loss per Week=(CO1+CO2-CI)*7/3500

This will give you your result in pounds. For a result in kg, simply divide your final answer by 2.2.

Now to calculate your projected weight loss for a certain date. This one is more complicated, and I suggest you use Excel.

First, open up Microsoft Excel, and duplicate all of the white cells into your spreadsheet. Make sure you type in the formulas exactly as you see them here. Input your own values into the yellow cells.

From the chart below, we can see that if a 75kg person eats 1300 calories a day, and burns 2000 just from being alive, plus another 200 in exercise, in 55 days, that person should theoretically weigh 60.8kg.