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.
| 2018
Pence | 2017
Pence |
|---|
| Basic earnings per share | | |
| — Underlying* | 76.85 | 64.68 |
| — Basic | 37.24 | 28.09 |
| Diluted earnings per share | | |
| — Underlying* | 76.45 | 64.33 |
| — Diluted | 37.04 | 27.93 |
The calculations of basic and diluted earnings per share are based upon:
| 2018
£m | 2017
£m |
|---|
| Earnings for underlying basic and underlying diluted earnings per share | 74.5 | 60.1 |
| Earnings for basic and diluted earnings per share | 36.1 | 26.1 |
| Number | Number |
|---|
| Weighted average number of ordinary shares for basic earnings per share | 96,942,002 | 92,962,967 |
| Impact of share options | 509,209 | 516,032 |
| Weighted average number of ordinary shares for diluted earnings per share | 97,451,211 | 93,478,999 |
* Underlying measures exclude non-underlying items as defined in the Consolidated Income Statement.
At 30 June 2018, there are 231,551 options (2017: 294,848) that are excluded from the EPS calculations as they are not dilutive for the period presented but may become dilutive in the future.