Year-over-year (YOY) growth is a performance metric that compares a specific business result, such as revenue, user count, or conversions, from one period to the same period in the previous year.

It’s used to measure long-term growth trends, filter out seasonal fluctuations, and evaluate business momentum over time.

YOY growth gives a clear picture of sustainable progress, beyond short-term spikes or seasonal dips. It’s commonly used in board reports, investor updates, and internal performance reviews to evaluate how well the company is growing year after year.

Formula:

YoY growth (%)=((This year’s value−Last year’s value​) / Last year’s value) × 100

Example:

If your SaaS company generated $1.2M in revenue this October, and $1M last October: 

YoY growth = ((1.2M - 1M) / 1M) x 100 = 20%.