v3.26.1
Remeasurement Items affecting operating profit - Assumptions (Details)
 12 Months Ended
Jun. 30, 2026
$ / bbl
$ / T
R / $
$ / gal
Jun. 30, 2025
R / $
$ / T
$ / gal
$ / bbl
Jun. 30, 2024
R / $
$ / T
$ / gal
$ / bbl
$ / kJ
Impairment assumptions      
Period over which management has projected cash flows 5 years    
Crude oil price (Brent) | $ / bbl 76.8 72.16 83.06
Ethane price | $ / gal 0.3126 0.334 0.3955
Ethylene price | $ / T 745.06 747 745
Linear low density polyethylene (LLDPE) price | $ / T 1,021.21 1,039.11 1,090.88
Polyvinyl Chloride (PVC) price | $ / T 786.93 878 980
Oil Product Differentials | $ / bbl 15.47 11.44 10.86
Refining margin | $ / bbl 9.81 7.54 8.11
Exchange rate | R / $ 17.09 18.31 17.64
Period for calculation of assumptions used for impairment calculations 5 years    
Average exchange rate over ten year period following initial five year forecast horizon | R / $ 19.77    
Percentage of strengthening (weakening) in average exchange rate over ten year period following initial five year forecast horizon 17.00%    
Percentage of assumed South African versus US inflation differential 2.00% 3.50%  
Average Brent crude oil price over ten year period following initial five year forecast horizon | $ / bbl 92.01    
Percentage of increase (decrease) in average Brent crude oil price over ten year period following initial five year forecast horizon (3.00%)    
Average North East Asia LLDPE price over ten year period following initial five year forecast horizon | $ / T 1,724    
Percentage of increase (decrease) in average North East Asia LLDPE price over ten year period following initial five year forecast horizon (8.10%)    
South Africa      
Impairment assumptions      
Southern African gas purchase price (real) | $ / kJ     0.00001051
Growth rate - Producer Price Index 4.00% 5.50% 5.50%
Weighted average cost of capital 11.50% 14.50% 15.00%
United States      
Impairment assumptions      
Growth rate - Producer Price Index 2.00% 2.00% 2.00%
Weighted average cost of capital 8.30% 9.10% 9.40%
Europe      
Impairment assumptions      
Growth rate - Producer Price Index 2.00% 2.00% 2.00%
Europe | Minimum      
Impairment assumptions      
Weighted average cost of capital 7.10% 7.60% 9.40%
Europe | Maximum      
Impairment assumptions      
Weighted average cost of capital 8.60% 10.00% 10.50%
Mozambique      
Impairment assumptions      
Growth rate - Producer Price Index 2.00% 2.00% 2.00%
Weighted average cost of capital 16.40% 18.40% 16.80%