Frontierville Energy Levels
Maximum energy increases at a rate of +1 every 2 levels until level 10. Then, a player will get +1 energy every 5 levels.
At level 1 a player has 10 energy, at level 2 it increases to 11.
At level 4 the maximum energy increases to 12, and so on until level 10 when a player has 15 energy.
A player stays at 15 Max Energy until level 15 when they’ll receive +1 to their maximum, bringing them up to 16.
After level 15 they’ll receive +1 every 5 levels, so at levels 20, 25, 30, 35, 40 and 45, +1 will be added.
After level 50, the player receives +1 to their max energy every 10 levels.

Frontierville Energy Levels
Remember that adding a spouse will give an additional 3 maximum energy and a kid will add +1. Some collections and quests will add to your max energy too, so read carefully when you complete a quest or collection.
You may also purchase Beef Jerky in the Market, which will +1 in addition to refilling your Energy Bar.
Here is a chart that will show you the maximum energy you will have on each level not including bonuses won from quest completion or energy from beef jerky:
