Net Dollar Retention
Definition
NDR is a churn metric that calculates the percentage of recurring revenue retained from existing customers over time.
Calculation
\begin{equation} {NDR}={\frac{Starting\ MRR\ +\ Expansion\ -\ Ccontraction\ -\ Churned}{Starting\ MRR}}\times{100} \end{equation}
NDR = ((Starting MRR + Expansion MRR - Contraction MRR - Churn MRR)/(Starting MRR)) * 100