Growth Index (GI)
8-week avg / 52-week rolling avg; >1.0 = growing, <1.0 = declining.
The Growth Index is a single number that tells you whether a service is growing, plateauing, or declining right now. It is calculated by dividing the 8-week rolling average by the 52-week rolling average.
A Growth Index above 1.0 means recent attendance is outpacing the annual trend — the service is growing. A value below 1.0 means attendance is slipping relative to the long-term baseline. A value near 1.0 indicates stability.
Because the Growth Index uses smoothed averages rather than raw week-to-week counts, it filters out noise from weather, holidays, and one-off events. You need at least 52 Sundays of data (Tier 3 maturity) before this metric becomes available.
Why it matters for your church: The Growth Index is the single best snapshot of directional health. Pastors and executive teams can monitor it weekly without getting distracted by the natural ups and downs of Sunday attendance. A sustained GI below 1.0 is an early warning that something has shifted — long before the change becomes obvious in raw numbers.