Calc Skyrim - Fireball

1:06

Fireballs explode to do some considerable damage. I'll have to look up to see if there are any examples of how big fireballs can be in the lore, but gameplay-wise, they can reach 15 feet (or 4.57200m) in radius.

A fiery explosion for 40 points of damage in a 15 foot radius. Targets on fire take extra damage.

Click to expand...

Put this through Nuke Map and mess around some and we get a fireball yield of 0.000797 kilotons (or 0.797 tons of TNT).

Final Results
Fireball = 0.797 tons of TNT