What it is
GRR (gross revenue retention) shows how much starting ARR you kept before giving credit for expansion. It isolates contraction and churn quality — the retention story expansion can hide.
How it’s calculated
Typically (starting ARR − contraction − churn) ÷ starting ARR, capped at 100%. Same cohort rules as NRR; only the expansion treatment differs.
Where it breaks
GRR breaks when downgrades are miscoded as churn (or vice versa), when logos move entities and look like churn+new, or when finance uses a different starting ARR than the waterfall.
In the board pack
Put GRR next to NRR on the retention slide. Investors read both; operators use GRR to target save motions.
Keep the written definition stable across close, the board pack, and diligence so the same word never means two math models.