Do you know how hot a pepper really is?

Small in size, big in impact: the pepper! Around 20% of the world's population regularly eats this vegetable, famous for its fiery kick. Ever wondered which pepper is the hottest in the world? We've lined up five peppers, from mild to seriously spicy.

The Scoville Scale

The heat of a pepper is measured using the Scoville Scale. This scale measures the amount of capsaicin, the natural compound responsible for a pepper's heat. Capsaicin stimulates the heat receptors on your tongue, creating that familiar burning sensation.

Interestingly, the Scoville Scale is mainly used as a comparison tool. The heat level can vary even between peppers growing on the same plant.

And the winner is...

Here are five peppers, ranked from the mildest to the hottest.

5. Bell Pepper

It may come as a surprise, but the bell pepper is actually a type of pepper. Since it contains no capsaicin, it scores 0 Scoville Heat Units (SHU).

4. Jalapeño

This popular Mexican pepper is considered mildly spicy, with a heat level of 2,000–8,000 SHU. Red jalapeños are generally hotter than their green counterparts.

3. Cayenne Pepper

You'll probably find cayenne pepper in powdered form in most spice racks. Don't let that fool you—fresh cayenne peppers measure 30,000–50,000 SHU, packing a respectable amount of heat.

2. Red Savina Habanero

It may look like a tiny bell pepper, but don't be deceived. The Red Savina Habanero reaches 350,000–577,000 SHU. Until 2007, it held the Guinness World Record as the hottest pepper in the world.

1. Carolina Reaper

The Red Savina Habanero has long since lost its crown. The Carolina Reaper tops the list with an incredible 1,500,000–2,200,000 SHU, making it one of the hottest peppers ever cultivated. Definitely not for the faint-hearted!