CARR vs ARR vs NRR vs GRR: The Metrics That Actually Describe a B2B Software Business

ARR: Annual Recurring Revenue

ARR is the annualized value of all recurring revenue that is currently live and being delivered. A customer paying $10,000 per month on an active subscription contributes $120,000 of ARR. One time fees, services, and signed but not yet live contracts are excluded.

CARR: Contracted Annual Recurring Revenue

CARR is ARR plus recurring revenue that is signed but not yet live: deals closed and contracted where onboarding has not finished or the start date has not arrived. CARR answers the question ARR cannot: what does the business look like once everything we have sold is running? For companies with implementation periods measured in weeks or months, the gap between CARR and ARR is one of the most honest indicators of onboarding health. A growing gap usually means sales is outrunning delivery, though read it as a signal rather than a verdict: contract structure, such as future dated start dates, can widen the gap with no onboarding problem at all.

GRR: Gross Revenue Retention

GRR measures how much recurring revenue you kept from an existing cohort over a period, counting churn and downgrades but ignoring expansion. Formula: starting ARR, minus churned ARR, minus contraction ARR, divided by starting ARR. GRR can never exceed 100 percent. It is the purest measure of whether customers keep what they bought.

NRR: Net Revenue Retention

NRR is the same calculation with expansion included: starting ARR, minus churn, minus contraction, plus expansion and upsell, divided by starting ARR. NRR above 100 percent means your existing base grows without any new logos. It is the metric investors quote first, because it compounds.

1. Mixing CARR into ARR without labeling it

Boards and investors assume ARR means live revenue. Counting signed but not deployed contracts inflates the number and erodes trust the moment anyone reconciles it against billing. Report both, label both, and let the gap tell its story.

2. Calculating NRR on a convenient cohort

NRR is a cohort metric. It only means something when the starting group is fixed and the window is consistent, typically trailing twelve months. Recalculating with friendlier cohorts is the fastest way to lose credibility in diligence.

3. Letting expansion hide churn

A 115 percent NRR can conceal an 80 percent GRR. That is a business replacing a leaky bucket with a bigger hose. Always report GRR next to NRR; the pair tells the truth that either one alone can hide.

4. Counting non recurring revenue as recurring

Implementation fees, one time services, and usage overages that do not repeat do not belong in ARR. The test is simple: would this revenue appear again next year if the customer changed nothing? If not, it is not recurring.

5. Tracking the metrics in spreadsheets instead of the system of record

When ARR lives in a spreadsheet maintained by one RevOps analyst, every board meeting starts with a reconciliation exercise. Retention metrics should compute from the same system that holds the contracts, the renewals, and the expansion pipeline. If your CRM cannot produce NRR without an export, the problem is the CRM's data model, not your analyst.

What is the difference between CARR and ARR?

CARR includes contracted revenue that has not gone live yet. ARR includes only revenue currently being delivered. CARR minus ARR equals your onboarding backlog.

Can NRR be high while the business is unhealthy?

Yes. High expansion from a few accounts can mask broad churn. Check GRR alongside NRR before drawing conclusions.

Should startups report CARR or ARR to investors?

Report both, clearly labeled. Sophisticated investors will ask for both anyway, and volunteering the distinction signals operational maturity.

How often should retention metrics be calculated?

Monthly for internal operating reviews, trailing twelve months for board and investor reporting. The cohort definition should never change between reports.