# Customer and Revenue Churn Calculator — Ireland

> Keep new-customer revenue outside the opening-cohort retention measures and allow genuinely negative net revenue churn. EUR planning view; stated limitations apply.

Page: https://askcalculators.com/ie/churn/
Definition: https://askcalculators.com/ie/churn/definition.json
JSON Schema: https://askcalculators.com/ie/churn/schema.json
Version: 20.16.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/ie/churn/?openingCustomers=1000&lostCustomers=30&openingMrr=100000&churnedMrr=3000&contractionMrr=1000&expansionMrr=5000

## Inputs
- openingCustomers: Paying customers at period start; type=number; required; default=1000; min=1; max=1000000000
- lostCustomers: Customers from that opening cohort lost in period; type=number; required; default=30; min=0; max=1000000000
- openingMrr: Recurring revenue from opening cohort; type=money; required; default=100000; min=0; max=1000000000000
- churnedMrr: Recurring revenue lost from opening cohort cancellations; type=money; required; default=3000; min=0; max=1000000000000
- contractionMrr: Recurring revenue lost from opening cohort downgrades; type=money; required; default=1000; min=0; max=1000000000000
- expansionMrr: Recurring revenue gained from opening cohort expansion; type=money; required; default=5000; min=0; max=1000000000000

## Outputs
- logoChurn: Opening-cohort customer churn, percent; format=number
- grossRevenueRetention: Gross revenue retention, percent; format=number
- netRevenueRetention: Net revenue retention, percent; format=number; primary
- netRevenueChurn: Net revenue churn, percent; format=number

## Formula
NRR = (opening recurring revenue − churn − contraction + expansion) ÷ opening recurring revenue.

Inputs are converted to canonical units before evaluating this stated formula.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: Illustrative defaults are not local quotes or verified legal rules. Dated reference components and user-entered assumptions are explicitly distinguished. Professional review is pending.