| Registered shares at 31 December 2022–31 December 2023 (no changes in 2024) | 897,264,465 | 3,046,185,953 |
| Registrations in 2022 | | |
| - registered shares in directed share issue without payment to Solidium Oy | 8,970,000 | |
| Registered shares at 31 December 2018 - 24 Nov 2022 | 888,294,465 | 3,046,185,953 |
| – cancellation of treasury shares on 21 Dec 2018 | 72,580 | |
| Registered shares at 31 December 2010 - 31 December 2017 | 888,367,045 | 3,046,185,953 |
| Registered shares at 31 December 2009 | 888,367,045 | 3,046,185,953 |
| – 2002 B share option scheme | 728,965 | 2,478,481 |
| Subscriptions with options in 2008 | | |
| – 2002 B share options scheme for key employees | 955,022 | 3,247,075 |
| Total shares and share capital on 31 December 2008 | 887,638,080 | 3,043,707,472 |
| Subscriptions with options in 2007 | | |
| – 2001 A share options scheme for key employees | 274,920 | 934,728 |
| – 2001 B share options scheme for key employees | 1,339,867 | 4,555,548 |
| – 2002 A share options scheme for key employees | 122,100 | 415,140 |
| – 2002 B share options scheme for key employees | 3,462,525 | 11,772,585 |
| Cancellation of own shares | -5,910,000 | |
| Total shares and share capital on 31 December 2007 | 886,683,058 | 3,040,460,397 |
| Subscriptions with options in 2006 | | |
| – 2001 A share options scheme for key employees | 3,026,200 | 10,289,080 |
| – 2001 B share options scheme for key employees | 5,360,133 | 18,224,452 |
| – 2002 A share options scheme for key employees | 516,800 | 1,757,120 |
| – 2002 B share options scheme for key employees | 4,856,488 | 16,512,059 |
| Cancellation of own shares | - 1,660,000 | |
| Total shares and share capital on 31 December 2006 | 887,393,646 | 3,022,782,396 |
| Subscriptions with options in 2005 | | |
| – 1999 bond loan with warrants | 1,284,370 | 4,366,858 |
| – 1999 management share option scheme | 1,698,000 | 5,773,200 |
| – 2001 A share options scheme for key employees | 1,636,350 | 5,563,590 |
| – 2002 A share options scheme for key employees | 3,591,400 | 12,210,760 |
| Share capital on 31 December 2005 | 875,294,025 | 2,975,999,685 |
| Subscriptions with options in 2004 | | |
| – 1999 bond loan with warrants | 4,560,730 | 15,506,482 |
| – 1999 management share option scheme | 7,154,000 | 24,323,600 |
| – 2002 A share options scheme for key employees | 6,536,700 | 22,224,780 |
| Share capital on 31 December 2004 | 867,083,905 | 2,948,085,277 |
| Subscriptions with options in 2003 | | |
| – 1999 bond loan with warrants | 159,520 | 542,368 |
| – 1999 management share option scheme | 2,913,000 | 9,904,200 |
| Share capital on 31 December 2003 | 848,832,475 | 2,886,030,415 |
| Subscriptions with options in 2002 | | |
| – 1999 bond loan with warrants | 148,380 | 504,492 |
| – 1999 management share option scheme | 3,000 | 10,200 |
| Share capital on 31 December 2002 | 845,759,955 | 2,875,583,847 |
| Share capital on 31 December 2001 | 845,608,575 | 2,875,069,155 |
| Script issue in 2000 | | 28,441,677 |
| Rights issue in 2000 | 60,825,940 | 206,808,196 |
| Share capital on 31 December 2000 | 845,608,575 | 2,875,069,155 |
| Share capital on 31 December 1999 | 784,282,635 | 2,639,819,282 |
| Fortum established on 7 February 1998 | 500,000 | 1,681,879 |
| Rights issue in 1998 | 782,782,635 | 2,631,409,886 |
| Employee issue in 1998 | 2,000,000 | 6,727,517 |
| Share capital on 31 December 1998 | 784,782,635 | 2,639,819,282 |