Net new ARR: definition, formula, and how to calculate it

Net new ARR explained: how to calculate net new ARR from new, expansion, contraction, and churned ARR movements - plus common mistakes.

Updated 2026-01-24

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Definition

Net new ARR is the net change in ARR for a period after adding new and expansion ARR and subtracting contraction and churned ARR. It's a core input to burn multiple and other SaaS efficiency metrics.

Formula

Net new ARR = new ARR + expansion ARR - contraction ARR - churned ARR

How to calculate net new ARR

  • Measure new ARR from customers acquired in the period (annualized recurring run-rate).
  • Measure expansion ARR from existing customers (upsells, seats, add-ons).
  • Measure contraction ARR (downgrades) and churned ARR (cancellations).
  • Apply the formula and keep the definition consistent across months/quarters.

Net new ARR vs growth rate

  • Net new ARR is a dollar amount (ARR).
  • ARR growth rate is net new ARR / starting ARR for the period.
  • Use growth rate for comparisons; use net new ARR for planning and efficiency metrics.

Reconciliation checklist

  • Starting ARR + net movements equals ending ARR for the same period.
  • Separate reactivations and price increases from expansion.
  • Normalize annual contracts to ARR, not billings.
  • Review net new ARR by segment to spot hidden churn.

Common mistakes

  • Mixing bookings/cash with ARR movements (different timing and definitions).
  • Using inconsistent windows (monthly net new ARR with quarterly burn).
  • Including one-time fees/services in ARR movements.

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