As explained in the [energy usage model](🔗), developers gain energy either from freezing TRX to get dynamically-allocated energy (frozen / network total * total available, currently 100 billion), or from burning TRX directly to obtain fixed energy (currently 1 energy = 10 sun).
Under normal circumstances, both strategies should provide enough energy for smart contract deploy/execution. However, due to the way _fee_limit_ is set up, if a developer freezes too much TRX for energy, this account's energy calculation is bound to the frozen model. The max energy this account can use is limited to **fee_limit (up to 1000 TRX) / total network frozen TRX * 100 billion**. If the upper bound is hit, an **OUT_OF_ENERGY** error will be thrown, without burning TRX. If the amount of energy frozen isn't too much, it is possible to combine both strategies to account for total used energy.
The specific formula is:
Developers can also use the user-friendly [energy calculator](🔗) to calculate the energy amount an account can use to deploy/execute smart contracts, and how much they will cost.
As general advice, developers are discouraged from freezing too much TRX (making it unfair for other developers). Otherwise, they are bound to the lower energy upper cap, rather than from burning TRX directly. If an account is in such a situation and a large contract needs to be deployed, try to either unfreeze some TRX or transfer TRX to a new account without frozen energy.