Expenses, Calculate cost of Miles or Km


Is there a way to have an Expense Type or category so when selected it allows you to enter Miles or Kilometres travelled and calculates at £0.45 pence per mile for example. If i enter 78 miles @ £0.45 per mile, then this calculates to = £35.10

Is there a way to have this in place? If so, please share on how to achieve this.

Many Thanks