I was wondering how to calculate my EER?

If you are talking about your maintenance calories, then the most accurate way is to spend a normal week, one where you don't change weight, writing down every single thing you put in your mouth. At the end of the week, work out how many calories you've eaten and average it out.

You'll have your maintenance calories, perfectly adjusted to take account of your activity level and lifestyle.

Here's the formula: for women; 247-2.67 X age + 401.5 X height + 8.6 X weight
For men: 293 -3.8 X age + 456.4 X height + 10.12 X weight