The heat of different chillies is measured using the Scoville scale, which marks the degree of dilution of the chilli sample in a sugar solution. A rating of 100,000 means the extract  had to be diluted 100,000 with the sugar solution for its heat to be undetectable.

Chilli Variety Scoville Rating
Naga Jolokia 855,000-1,041,427
Dorset Naga 876,000-970,000
Red Savina Habanero, Chocolate Habanero 350,000-577,000
Habanero, Scotch Bonnet, Rocoto 100,000-350,000
Scotch Bonnet 100,000-350,000
Jamaican Hot 100,000-200,000
Thai, Malagueta, Tepin (Chiltepin) 50,000-100,000
Cayenne, Aji, Tabasco, Numex Twiliight 30,000-50,000
Serrano 10,000-23,000
Tabasco Sauce (Habanero) 7,000-8,000
Wax 5,000-10,000
Jalapeno 2,500-5,000
Tabasco Sauce (Tabasco Pepper) 2,500-5,000
Rocotillo 1,500-2,500
Poblano 1,000-1,500
Tabasco Sauce (Green Pepper) 600-800
Anaheim 500-1000
Pimento, Pepperoncini 100-500
Bell Pepper, No Heat 0