Where our heat figures come from
Every Scoville figure on this site needs a good reference. Below is each chilli's range, what that range means, where sources disagree, and a reference list with a link to every source, in Harvard style. We are happy to be challenged on our figures: if you think one is wrong, use the link under it and send us a reference.
Figures last checked: 11 October 2026.
Draft. The figures on the chart have not all been checked against their sources yet. Each entry below says whether we have marked it as verified.
Why sources differ
You will see the same chilli given different ranges by different sources. There are a few reasons, and we do not always know which applies:
- Where and how it is grown. New Mexico State University's chilli breeders say their listed heat levels are averages that can vary by year and growing location (Coon et al., 2022). So a figure from North Carolina and one from Florida might both be honest and still differ.
- Plant to plant. In one New Mexico State University trial, single plants of the same variety differed enormously (Bosland et al., 2012).
- Where the figure came from. Many extension pages give a typical range and do not say whether they measured it themselves. We have not been able to confirm that for most of them.
- The conversion. Laboratory results are turned into Scoville units with a factor that is not settled, from 15 to 16.1 (Hayward et al., 2026).
Where good sources disagree we show both. Read more on how the scale works.