How are staking rewards calculated?

There’s no short answer here. Each blockchain network may use a different way of calculating staking rewards.

Some are adjusted on a block-by-block basis, taking into account many different factors. These can include:

• how many coins the validator is staking
• how long the validator has been actively
  staking
• how many coins are staked on the network in total
• the inflation rate
• other factors

For some other networks, staking rewards are determined as a fixed percentage. These rewards are distributed to validators as a sort of compensation for inflation. Inflation encourages users to spend their coins instead of holding them, which may increase their usage as cryptocurrency. But with this model, validators can calculate exactly what staking reward they can expect.

A predictable reward schedule rather than a probabilistic chance of receiving a block reward may look favorable to some. And since this is public information, it might incentivize more participants to get involved in staking.