I use the guestimate and as long as you know say a ball park % and weight with a finished weight or volume of the oil/resin you can get hand grenade close and at least keep yourself off the floor. Say you squish 1g 15% and get 20% as live resin ballpark is 150 mg / .20g you will never be @ 100% extraction so one gram of live resin would be in the ballpark of 600-750 mg thc a 20% variance. This is close because the chances are your pot is more than 15% and you are extracting closer to 80% or less
So yeah I can see one gram putting you on the floor. I did this once I made my tincture (one wash) and squeezed it all out. I then ran a shot of gin through as a second wash and made an iced tea highball....lol that was with 7 grams flower. I was sooo close to green out, flat on the floor with one foot upon the couch for orientation.
or
you decide lol