Calorie Calculator
Calorie Calculator for Non-Custom Meal Plans
This is the calorie calculator I recommend, the site says "weight loss calculator" but it can be used for both weight gain & loss.
*Remember! calculators are never 100% accurate so adjust your calories as you see fit. (ex: if you aren't gaining/losing, add/subtract 100-200 calories & so on).
Pick a calorie plan that is closest to what you need for you and your goals and make any adjustments from there.