The unit of measure for the Scoville scale is the Scoville Heat Unit or commonly referred to as the SHU. When the tests were devised chillies were relatively tame so something like a jalapeño which measures up to 10,000 SHUs and the tabasco pepper which is anywhere up to 50,000 SHU would have been maxing out the scale!
But in today's terms these measures are almost considered negligible with peppers like the Trinidad 7 Pot hitting 1 million SHUs and the former World Record Holder, Australia's Own Trinidad Scorpion "Butch T" tapping out at just under 1.5 million SHUs.
In August 2023 a new Guinness World Record holder was crowned, Pepper X measured in at AVERAGE of 2.693 Million SHUs, grown in the USA by Smokin' Ed Currie from the Puckerbutt Pepper Company, surpassing his last Guinness World Record in 2013 for the Carolina Reaper which came in at 2.2 Million SHUs on the Scoville scale.
For a short time it looked like UK grown Dragon's Breath was going to take the crown measuring at 2.48M SHUs but it was never officially recognised and in the meantime Pepper X has come through and won the day.