Timing a specific fetch call

I am making a fetch call like so fetch("foo.com/x.json") and would like to get the time it takes to make the request as it is reported in dev tools.

I have already tried,

performance.mark("fetch-start");
let start = performance.now();
let res = fetch("https://example.com/foo.json", {});
res.then(r => {
  performance.mark("fetch-end");
  performance.measure("fetch", "fetch-start", "fetch-end");
  var measures = performance.getEntriesByName("fetch");
  var measure = measures[0];
  console.log(measure);
});

Have also tried performance.now() -start and they are not as accurate as the devtools, I'm guessing this is due to the fact that the browser does more than one thing at once and doesn't spend all it's time measuring things in isolation.

Is there a way to get as accurate as Developer tools for network timing?

from Timing a specific fetch call