My GUI Timer is inaccurate, takes longer for seconds to pass?

Hi everyone!

I was making a timer which would start counting from 0, and go in milliseconds (similar to a speedrun timer). Here is what i tried to do:

if isRunning == false then
	isRunning = true
	local timer = script.Parent -- a text label
	local milaseconds = 0 -- totally correctly spelled
	local seconds = 0
	local minutes = 0
	while isRunning == true do
		wait(0.0001)
		milaseconds += 1
		if milaseconds == 100 then
			milaseconds = 0
			seconds += 1
			if seconds == 60 then
				seconds = 0
				minutes += 1
			end
		end
		timer.Text = minutes .. ":" .. seconds .. "." .. milaseconds -- no bad spelling here
	end
end

The timer ends up taking way too long, a second in the script is around 2.5 seconds irl. Can anyone please help me make this timer more accurate?

Thanks in advance :)

The lowest wait() you can have is 1/30 of a second, if you wish to go lower, use RunService.Stepped/RenderStepped, which is 1/60 of a second.

Wait() is inaccurate and should not be used for precise timing. You should use tick() or runService instead