Measuring reach

I’m replacing the bars and stem on my wife’s roadie. In figuring out what length stem to get, I need to compare the reach of the new bars with the old ones.

I’m getting 110mm reach measuring from the centre of the flat section to the centre of the bar at its most frontal point. Like this (right image):

110mm seems like a lot to me. The new bars are 80mm, according to the manufacturer. So 30mm more stem.

I’ve also seen diagrams suggesting I should measure right to the end of the bars. That would make it 120mm+, surely too long?

Also, what is the correct angle for measuring the reach section? Should the reach section be horizontal (ie flat on top), should the drop section be horizontal (like the image above), or should I measure it like I have them angled on the actual bike (that would be assuming the new reach is measured similarly - that is what I’ve done currently)?

the most practical way would be to measure in the position the bar would be fitted to the bike

you also need to bear in mind where you plan to mount the levers because that changes the real world reach too

the best thing you can do is try and borrow a few stems to work out which feels best rather than trying to match numbers on paper which really never works