Final Cut Pro exports larger than original file?

They just use different rate rates. If you look in an application like MediaInfo you'll see details of what was shot and what the output files are. Usually high end cameras shoot very high data rate formats even when using H.264, so it's surprising your files for one hour as so very small, 1GB an hour is amazing.

Virtual conference as in Zoom video? They use a very low data rate for their content, of course they're usually fairly easy content to compress. If you want a comparable data area you need to use Compressor or Handbrake to get more control. The FCP export settings are usually quite high to cover more active video.

File size = duration X bitrate.

If you want smaller files, you need to lower the bitrate.

The original files you are using as source media have an extremely low bit rate to enhance their use in streaming, the default exports from FCP-X use a much higher bitrate it assumed you want high quality output.

As others have stated, use either Handbrake or Apple Compressor to transcode the file you have exported with a low bitrate to get the end file size you want.

MtD

As you are just chopping it up with no frills e.t.c you may find that iMovie will do what you need.

iMovie has a variable bit rate setting in File>Share>File>Quality >Custom.

You can see the file size vary as the slider for bit rate is adjusted.

Experiment with a small section first to see if it gives you what you want.

You might want to select Compress for Better Quality rather than Compress Faster .

As Tom explained it’s mostly in the data rate and a few other variables.

FCP exports/shares at fixed data rates and they cannot be altered.

However, FCP can work with Apples’ Compressor App so you have customisable control over the output.

Typically you create a setting in Compressor then apply that in FCP, this is then Shared from FCP as easily as one of the FCP Presets.

The price is a steal for what your get IMO.

Al