Group balance sheet (Parenthetical) shares in Millions	6 Months Ended
Jun. 30, 2021 shares
Rio Tinto Plc
Statements [Line Items]
Weighted average number of ordinary shares outstanding (in shares)	1,247.8
Rio Tinto Limited
Statements [Line Items]
Weighted average number of ordinary shares outstanding (in shares)	371.2

The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2020-01-01
-Paragraph 70
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2020-en-r&anchor=para_70_b&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_WeightedAverageShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration