Custom Dashboards now support equations for the Application Metrics dataset. Equations allow you to combine multiple metrics into a formula. You can answer simple questions, like what percentage of events are errors, or build complex calculations like Apdex.

Save an equation from Explore to a new or existing Dashboard, or create an equation-backed widget directly from a Dashboard by choosing the Application Metrics dataset.

Application Metrics is available to every Sentry user. Read the setup docs for your language.