Basic earnings per share

The calculation of basic earnings per share at 31 March 2017 was based on the profit attributable to ordinary shareholders of £12.7m (2016: £10.2m) and a weighted average number of ordinary shares outstanding during the year ended 31 March 2017 of 118,493,886 (2016: 116,388,265), calculated as follows:

Weighted average number of ordinary shares

20172016
Issued ordinary shares at 1 April116,747,887116,174,086
Effect of shares issued1,745,999214,179
Weighted average number of ordinary shares at 31 March118,493,886116,388,265

Diluted earnings per share

The calculation of diluted earnings per share at 31 March 2017 was based on profit attributable to ordinary shareholders of £12.7m (2016: £10.2m) and a weighted average number of ordinary shares outstanding during the year ended 31 March 2017 of 122,143,769 (2016: 120,345,662), calculated as follows:

Weighted average number of ordinary shares (diluted)

20172016
Weighted average number of ordinary shares at 31 March118,493,886116,388,265
Effect of share options on issue3,649,8833,957,397
Weighted average number of ordinary shares (diluted) at 31 March122,143,769120,345,662

The average market value of the Company's shares for the purposes of calculating the dilutive effect of share options was based on quoted market prices for the period that the options and deferred equity awards were outstanding.

Underlying earnings per share

EPS (total)2017
EPS
2016
EPS
Earnings
£000
BasicDilutedEarnings
£000
BasicDiluted
Profit after tax for the financial year12,69810.72p10.40p10,2258.78p8.50p
Separately disclosed items:
IFRS2 share based payment charge1,5121.28p1.24p1,6871.45p1.40p
Acquired intangible amortisation1,2731.07p1.04p9740.84p0.81p
Net acquisition costs2640.23p0.22p
Costs on exercise of
executive share options5670.48p0.46p
Profit on sale of fixed assets(195)(0.17p)(0.16p)
Tax charge on adjusted items^(193)(0.16p)(0.16p)(1,132)(0.97p)(0.94p)
Underlying profit after tax15,66213.22p12.82p12,01810.33p9.99p

^ For the 2016 calculation this includes adjusting for the recognition of the deferred tax asset in TR Fastenings Inc

The 'underlying diluted' earnings per share is detailed in the above tables. In the Directors' opinion, this best reflects the underlying performance of the Group and assists in the comparison with the results of earlier years (see note 2).