Initial estimations are that the change is expected to cost around £50m a year by the end of the forecast period (2015-16).

"For the balance of the forecast period, we expect plentiful and affordable fuel."

The value of the target company after the forecast period can be calculated by:

Each line beginning with FM starts a new forecast period.

Cash flows after the forecast period can only be represented by a fixed number such as annual growth rates.

There are no fixed rules for determining the duration of the forecast period.

This article covers three methods of determining the forecast period.

Determine a forecast period by choosing a number of years with excessive return.

Determine a forecast period by choosing a number of years after which an exit is planned.

At Budget 2010, the end of the forecast period was 2015-16.