Earnings per ordinary share (Tables)

12 Months Ended

Dec. 31, 2018

Summary of earnings (loss) per ordinary shares

				2018					2017
			Weighted						Weighted
			average			2018			average		2017
		2018	number of		Per share		2017		number of		Per share
	Earnings		shares		amount		Earnings		shares		amount
	US$m		(millions)		(cents)		US$m		(millions)		(cents)
Basic earnings per share attributable to ordinary
shareholders of Rio Tinto^(a)		13,638		1,719.3		793.2		8,762		1,786.7		490.4
Diluted earnings per share attributable to ordinary
shareholders of Rio Tinto ^(b)		13,638		1,731.7		787.6		8,762		1,799.5		486.9

2016

Weighted

average

2016

number of

Per share

Earnings

amount

US$m

(millions)

(cents)

Basic earnings per share attributable to ordinary

shareholders of Rio Tinto ^(a)

4,617

1,797.3

256.9

Diluted earnings per share attributable to ordinary

shareholders of Rio Tinto^(b)

4,617

1,808.6

255.3

(a)

The weighted average number of shares is calculated as the average number of Rio Tinto plc shares outstanding not held as treasury shares of 1,312.7 million (2017: 1,364.5 million; 2016: 1,373.7 million) plus the average number of Rio Tinto Limited shares outstanding of 406.6 million (2017: 422.3 million; 2016: 423.6 million) over the relevant period. No Rio Tinto Limited ordinary shares were held by Rio Tinto plc in any of the periods presented.

(b)

For the purposes of calculating diluted earnings per share, the effect of dilutive securities of 12.4 million shares in 2018 (2017: 12.8 million; 2016: 11.3 million) is added to the weighted average number of shares described in (a) above. This effect is calculated under the treasury stock method. In accordance with IAS 33 “Earnings per share”. The Group’s only potential dilutive ordinary shares are share options for which terms and conditions are described in note 43.