SaaS revenue forecasting is the process of predicting future revenue for subscription-based businesses. It combines historical performance, customer lifecycle data, and pipeline insights to project Monthly Recurring Revenue (MRR), Annual Recurring Revenue (ARR), renewals, and expansions. For SaaS companies, forecasting isn’t just about hitting a number for the quarter. It’s about aligning cash flow, growth targets, and investor expectations with what’s really happening across sales, renewals, and product usage.