The amount of Pyromancy needed for the spell depends on the size of the fire produced. Lighting a candle requires minimum magic and experience, but creating a wildfire can only be done by an advanced Pyromancer. It does, however, require a larger and more concentrated burst of magic than the Heating Spell. Inexperienced wizards may, instead of lighting a candle, just melt the candle into a puddle.
Lighting a candle:14 kgms (8.232 Ag)
Creating a campfire:25.477 kgms (14.98 Ag)
Creating a wildfire: Depends on how big the wildfire must be, but over 112 kgms (65.856 Ag) is not allowed by the Wizard Council. For creating enough fire to be called a "wildfire", about 51 kgms (29.988 Ag) are required.
The Fire Summoning Spell creates fire.