ARR captures the annualized value of all subscription contracts in force at a point in time. Monthly subscriptions are multiplied by 12; annual contracts are taken at face value. ARR excludes one-time fees, professional services, and any non-recurring revenue.
ARR is the standard SaaS metric for size and growth. Growth in ARR (new + expansion − churn − contraction) is the most-watched number in board meetings. Two companies at $10M ARR can have very different growth efficiency, retention, and capital intensity, so ARR alone never tells the full story.