A little confused about calculating calories required

If I understand right, in order to gain mass I need to take my BMR + 300-500 calories per day...

I've tried out a few calculators and some ask for activity level others don't. The calculations are quite different depending on if activity level is asked. The Harris Benedict calculator I used didn't ask for activity and shows my BMR as 1697. The one calc I used that did ask for my activity level it put my BMR at 2379.

Should I take activity level into account or not?

I have a sedentary job. I plan to lift weights 5 days per week for 1 hour each session.

I'm 5'9", 160lbs, 36yo.

So my question is should I consider my hour daily weight training when calculating my calorie requirements?

What should my base number be?

P.S. I realize this varies by individual. I just need a place to start.

Use a generic online TDEE calcuator to estimate your maintenance calories, such as this one: [url]https://tdeecalculator.net/[/url]

For activity level, you can start wherever you want, but I would say pick either lightly active or something between lightly and moderately active...

From there, add about 200 to the maintenance recommendation it gives you and monitor your weight gain using a 7-day moving average.

The 2379 number sounds reasonable to maintenance, I would say start at 2500-2600 calories and see where you land, 2600 if you're concerned about spinning your wheels.

Thanks Adam!