Why is the exported video so much larger than the original source video

[ReallyFelix]

I recorded an online conference with OBS Studio (https://obsproject.com/), which by-the-way, is an incredible open source application. The size of the recorded MP4 file is about 310MB. All I did was edit the file to remove a few minutes of video from the front and back of the source. I can't figure out a away to get an exported file to match the source video and be around the same size. All the exports I've tried come in at about 2GB.

I'm using H.264 format with a preset of Match Source - Adaptive High Bit Rate. The estimated file size is 545MB, which is close, but it comes in at 2GB.

Can someone recommend a tutorial or possibly explain how to accomplish this? Thank you!

Here are the specs of the file:

[Brandon Loshe]

That is strange why your final video is resulting in a file size so much larger than the estimated file size. Normally Premiere's estimation is pretty close. Although with your video being close to 2 hours (not sure how much time you shaved off), I would think that 2 GB sounds about right, even for 1280x702. Can you send a screenshot of your export settings?

I normally use the YouTube or Vimeo presets and then bump up the bitrate and make sure it is set to 2 Pass. 

[ReallyFelix]

Thanks for your quick reply Brandon. I've been testing with different options and get similar results.

I definitely understand that 2 GB is about right like you said, but I don't understand how the original is only about 300 MB and even the estimate during encoding is about 545 MB. I must be doing something wrong or not understanding something. I'm new to this so I think I need more education.

[Michael Grenadier]

screen recordings are usually both variable frame rate (which can cause other issues) and variable bit rate which is what I think is causing the discrepancy.  there was a thread here a month or 2 ago with someone complaining about the exported file size that seemed to be caused by variable bit rate...  you might do some searching here.