Try this stopwatch link:
. . . and see what is your fastest double-click time. It took me several tries to get down to 0.124. Using the fingers of two hands, sequentially, I could get 0.049.
0.113 after about 10 tries.
0.112 in about a dozen tries.
Just tried three more times, 0.100. I am really done now.
0.097 after about 10 tries.
Thats a windows setting isn’t it? I think in control panel.
I tried it 10 times. My best was .2. Most times it was .3 or .4 I got one .5
.109 after several tries, plus moving my hand farther forward on my mouse than usual. (It actuates the switch sooner if clicking from near the end of the button.) I think that’s close to the bounce time of the switch; when I tried to use both hands, going faster resulted in only one click registering.
ETA:
The setting controls how fast you have to click for Windows to recognize it as a double-click, not how fast you can click it.
I’m only getting results to the nearest tenth. .1, .2,.3
How are you getting .109?
3 goes each on left and right hand. 0.18 on left and 0.15 on right were the best.
Mine doesn’t even stop when I hit stop. I have to mash the left mouse button to get it to register.
Does that mean it’s too fast? 
There’s something off about this, maybe.
When I think I really, really got a good pair of clicks in, the number was higher than average (around .18-.19). But if I took it easy, then average or better (<.16).
Psychology? Rounding issues in code? Task switching oddities? ???
.103 , cookie clicker training to the rescue!
0.098 was my best of ten tries.
.113 in about ten tries. I got 0.075 with my graphics tablet on my first try, but that must have been a fluke, as after that the typical range was 0.125-0.175.
ETA: Oh, I didn’t realize you can constantly click. Doing that, I got my mouse click to 0.087, but the “typical” range is 0.110-0.125
After several tries I was able to get it down to .057.
Trying it out on a laptop where I can just double tap the pad for double click, I could get down to 0.046 with one hand (but two fingers, like playing a trill on a piano). Actually, trying it again, I got a fluke outlier of 0.029. The more typical range for the “trill” method is 0.60-0.75 for me, with about one in twenty hitting the 40s.
got .130 after about 10 or so tries. Basic logitech mouse.
Standard ordinary-everyday doubleclick speed seems to be 0.169 or thereabouts.
I don’t get much faster when deliberately trying for fast, though: 0.151
Cheating and holding mouse stationary with right hand and coming at it with middle finger of the left, 0.115
.130 range. My mouse is wireless though, so I’m blaming it on that.
Depends what I’m viewing…
Tried it about 8 times before I got bored. Best time was 0.088.