While revenue is the top line metric on the income statement, ARR works more like a balance sheet metric: it is taken at a single point in time rather than over a period of time. This can make income statements confusing and misaligned - another example of the divergence of accounting in economics in subscription businesses.

Now back to calculus... if the ARR function was actually a mathematical equation, you could integrate it. If y = 10x where y = ARR and x = time in months, then after two months ARR = $20. After 12 months, ARR = $120 (assuming we start from $0 of ARR). So at the end of a year, the business has grown from $0 to $120 in