Any anomalies associated to projected cost are usually due to timing. The monthly projected cost metric tends to get more accurate as the month progresses so numbers showing early in a new month may seem off. Below is how they are calculated.

The Projected Cost is calculated through linear extrapolation:

`(Actual MTD cost) + [(Average daily cost based on the last 31 days) x (Remaining days in the month)]`

As such, the Projected Cost is merely a guide that becomes more accurate as the month progresses and more actual MTD data is available. Be advised that CloudHealth does not calculate the Projected Monthly Cost for Reserved Instance purchases and one-time purchases such as Support.

Additional information regarding the Total EC2 Cost and the Total EBS cost to use for projection:

Total Cost = EC2 Total Cost + EBS Total Cost

EC2 Total cost = EC2 Compute cost + EC2 Transfer Cost

EBS Total Cost = EBS Storage Cost + EBS PIOPS Cost + EBS I/O Costs