 What is gender equality in science? The principle is widely embraced, but success can be hard to define or measure. There are many dimensions to equality, as shown by these different definitions and indicators. Each of these eight aspects of equality is important, but incomplete. Many contain ambiguities or contradictions, and this list is not exhaustive. To illustrate, gender pay parity is necessary, but not sufficient for gender equality in science. If women receive equal pay for equivalent roles, but don't have full access to leadership, that's not equality. Focusing too narrowly on any one aspect of equality can have unintended consequences. For example, increasing the number of women in historically male disciplines is important for many reasons, but a rigid focus on this goal can overlook other issues and reinforce the notion that men's work is more important than women's work. Not only does equality have many dimensions, but it's also connected to other problems. Objective assessment of performance at work, regardless of gender, is an essential component of equality, but many other aspects of our identity also affect how we judge others. Metrics can remove this subjectivity, but entrench systemic bias. The first four indicators here dis-deal solely with the work domain. The final four incorporate aspects of work-home conflict, which is both a major cause and consequence of gender inequality in our profession. Equal workforce participation is not equality if women still bear the brunt of domestic labor, and yet, splitting domestic labor 50-50 is not always practical or desirable. The final two indicators deal explicitly with competing demands of a career in science and parenting and expose how our personal values affect our perceptions of equality. Metrics are essential for assessing progress and holding leaders to account. Narrow application of equality metrics, however, can undermine other aspects of equality and mask some of the implicit assumptions that perpetuate gender inequalities in science.