Earnings per ordinary share has been calculated by dividing the profit attributable to equity holders of the parent after taxation for each financial period by the weighted average number of ordinary shares in issue during the period.

2017
Pence
2016
Pence
Basic earnings per share
— Underlying*64.6842.95
— Basic28.0914.00
Diluted earnings per share
— Underlying*64.3342.65
— Diluted27.9313.90

The calculations of basic and diluted earnings per share are based upon:

2017
£000
2016
£000
Earnings for underlying basic and underlying diluted earnings per share60,13238,390
Earnings for basic and diluted earnings per share26,11012,512
NumberNumber
Weighted average number of ordinary shares for basic earnings per share92,962,96789,380,414
Impact of share options516,032628,307
Weighted average number of ordinary shares for diluted earnings per share93,478,99990,008,721

* Underlying measures exclude non-underlying items as defined in the Consolidated Income Statement.

At 30 June 2017, there are 294,848 options that are excluded from the EPS calculations as they are not dilutive for the period presented but may become dilutive in the future.