In terms of overall size and composition by party/group, gender and peerage type:
- The total membership of the House was 797.
- Of this total, 778 Members were eligible to attend proceedings.
- The 19 Members ineligible to attend were either on leave of absence or disqualified from participating because they were serving in a senior judicial role.
- The Conservatives were the largest party or group with 244 Members. The Crossbench group were the second largest with 179 Members, while Labour had 177 and the Liberal Democrats counted 90.
- Women comprised less than a third of each main party/group, except one. Female Members accounted for just over one third (35.6%) of the Liberal Democrat party/group. Almost one third of the Labour party/group were women (32.8%).
- Over 85% of Members eligible to attend were life peers, with the remainder comprising excepted hereditary peers and senior Church of England prelates.
In terms of composition by age and different lengths of service:
- The mean average age of all Members was 70.
- The highest concentration of Members in each party/group fell in the 70–79 age band, except the bishops, whose Members mostly fell in the 60–69 age band.
- The youngest Member was Baroness Penn (Conservative), aged 35. The youngest male Member was Lord Parkinson of Whitley Bay (Conservative), aged 36. Of the eligible membership, 3.7% were aged under 50.
- The oldest Member was Lord Christopher (Labour), aged 95. The oldest female Member was Baroness Gardner of Parkes (Conservative), aged 92.
- Lord Denham (Conservative) had the longest length of service, having served for 70 years.
- Lord Greenhalgh (Conservative) had the shortest length of service. Along with Lord Grimstone of Boscobel (Conservative), he became a Member in April 2020.