[5] This is similar to Ma'aser kesafim (giving 10% of income) in Jewish tradition and zakat[6] in Islam, but Ord said there was no religious motivation behind it.

[7] By the end of 2011 it had 177 members, mostly other academics, in five chapters including Oxford, Cambridge, Princeton, and Harvard.

[12] Ord relied in part on research conducted by GiveWell, and also used the concept of the quality-adjusted life-year to gauge effectiveness of charities.

[13] In 2011, a sister organisation at Oxford led by MacAskill and others called "High Impact Careers" was spun off from Giving What We Can.

[19] In its early days, it recommended a selected set of charities in the area of global health.

[13][22] It believed that the variance in cost-effectiveness of charities arose largely due to the variance in the nature of the causes that the charities operate in, and therefore made evaluations across broad areas of work such as health, education, and emergency aid before comparing specific organisations.

[12] In 2017, the Centre for Effective Altruism stopped conducting original research into giving opportunities based on significant overlap with organisations like GiveWell and the Open Philanthropy Project.

All members share a commitment to donating at least part of their income and are commonly referred to as "pledgers."

[27] Founder Toby Ord further pledged to donate anything he earned over £20,000 a year, based on his conviction that he could live comfortably and happily on this income.