SaaS Metrics

ARR Waterfall

An ARR waterfall reconciles starting ARR to ending ARR using new, expansion, contraction, and churned ARR movements.

Updated 2026-01-23

Definition

An ARR waterfall reconciles starting ARR to ending ARR using new, expansion, contraction, and churned ARR movements.

Formula

Ending ARR = starting ARR + new ARR + expansion ARR - contraction ARR - churned ARR

Example

Start $2.0M; +$300k new; +$200k expansion; -$80k contraction; -$120k churn = $2.3M ending ARR.

How to use it

  • Use it as a reporting bridge to compute net new ARR and ARR growth.
  • Segment by plan/channel/customer size to avoid blended averages hiding churn pockets.
  • Use net new ARR as the numerator base for burn multiple (same period).
  • Reconcile waterfall totals to your ARR snapshot each period.

Common mistakes

  • Mixing bookings or cash with ARR movements.
  • Double-counting expansion as new ARR for the same account.

Measured as

Ending ARR = starting ARR + new ARR + expansion ARR - contraction ARR - churned ARR

Misused when

  • Mixing bookings or cash with ARR movements.
  • Double-counting expansion as new ARR for the same account.

Operator takeaway

  • Use it as a reporting bridge to compute net new ARR and ARR growth.
  • Segment by plan/channel/customer size to avoid blended averages hiding churn pockets.
  • Use net new ARR as the numerator base for burn multiple (same period).
  • Keep ARR Waterfall consistent by cohort, segment, and period before you use it as a decision signal in planning or reporting.
  • Interpret the metric alongside retention, margin, or payback so one ratio does not hide the real operating trade-off.

Next decision

  • Quantify the impact with ARR Waterfall Calculator if you need to turn the definition into an operating assumption.
  • Read ARR waterfall: reconcile starting ARR to ending ARR (net new ARR) if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.

Where to use this on MetricKit

Calculators

Guides