I've been carrying 6.6 pounds on my day hikes in my REI Flash 18 backpack including 3 liters of water, lunch and fuel. For Florida hiking in the summer, that's about enough water for half a day without refilling. The bad news is the weight of a few items is way too much to be considered for "Lightweight or Ultra-lightweight Backpacking".
My favorite (for 25 years) Swiss Army knife (3.7 oz) weighs more than any other item except rain gear/shelter and my cook pot. I knew that it was heavy and would have to go at some point. I'll surely miss it.
My compass also seems light at 1.1 oz but I have a lighter one at 0.4 oz that will work for everything except cross country travel.
I have also been carrying a rain poncho as an emergency tarp with rope and stakes but they total 26.3 oz. My current 12 oz rain jacket will be just fine. I'll get a SOL emergency bivy at 3.8 oz for that emergency overnight I never really expect to have.
My first aid kit also grew from 2.3 oz to 4.3 oz due to adding extra medications, bandages and a small pocket knife with scissors. I'll just replace my heavy knife with this smaller one for all but Western sojourns and through-hikes.
I also have an ounce of carabiners I love but do not use. They mainly jingle while I walk so I'll reduce them to one for clipping my Platypus water bottle on my pack straps (no side pockets).
Then there is a micro backup flashlight at 0.6 oz (go ahead and call me an Eagle Scout, I earned it) and a 3.7 oz monocular I rarely use. Since I already have a small headlamp with new batteries, I'll leave the backup micro light at home and will only bring the monocular when accompanying my birding friends (or looking at peaks in the Rockies).
As for the rest, I'll continue to carry Micropur tabs for emergency water purification, 50 feet of line and my cook kit (in cooler weather) and can now reduce my pack weight about 2 pounds to an easy 4.5 lbs. I will reweigh it for you at the next outing.