What Is Net Dollar Retention? The SaaS Metric Explained

What is net dollar retention and why do investors treat it as the single most important SaaS metric? It is the percentage of revenue retained from existing customers after accounting for churn, downgrades, and expansion — a score above 100% means the existing customer base is growing on its own, without any new customer acquisition.

This guide covers the formula, what counts as a strong score at different stages, and how to calculate it from a billing export.

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What is the formula for this metric?What score counts as world-class for enterprise SaaS?How does it differ from gross revenue retention?How do I calculate it from a Stripe or billing export?Why do investors care about this metric more than growth rate?

What this export contains

Customer ID

Start MRR

Churn MRR

Contraction MRR

Expansion MRR

End MRR

NDR %

Cohort Month

What usually goes wrong with it

Churn, contraction, and expansion all need to be tracked separately
A single net revenue number hides the story. A score of 105% could mean 0% churn with 5% expansion, or 20% churn offset by 25% expansion — very different business health signals.
DataMimi Track churn, contraction, and expansion in separate columns — build a waterfall view that shows the starting base, then subtracts churn and contraction and adds expansion to reach the ending figure.
Annual vs monthly calculation periods give different results
Monthly NDR fluctuates with billing cycles and one-time events. Annual cohort-based calculation is more stable and more comparable to public company benchmarks.
DataMimi Calculate on an annual cohort basis — group customers by the year they signed and measure their combined revenue 12 months later. This smooths billing cycle noise and gives comparable results.
Multi-year contracts distort the denominator
If a customer signs a three-year contract paid annually, when does their MRR appear in the starting base? Inconsistent treatment creates NDR numbers that can't be compared period to period.
DataMimi Use Datamimi to analyze your billing export — upload your subscription data and ask Datamimi to calculate the score by cohort, segment by plan type, and identify which cohorts have the best retention.

Common questions

What is net dollar retention and how is it calculated?

It is (Starting MRR − Churn MRR − Contraction MRR + Expansion MRR) / Starting MRR × 100. A score above 100% means the existing customer base is growing without new customer acquisition.

What is a strong score for a B2B SaaS company?

Top-quartile SaaS companies score 120%+. Median performers reach 100–110%. Below 90% indicates that expansion isn't keeping up with churn and the existing base is shrinking.

How does this metric differ from gross revenue retention?

Gross revenue retention only accounts for losses (churn and contraction) and is capped at 100%. This metric adds expansion, which is why it can exceed 100% and is a more complete view of customer health.

How does Datamimi help calculate this figure?

Upload your billing or subscription export with MRR columns and ask Datamimi to calculate the score by cohort, identify the best- and worst-performing segments, and flag trend changes.

How much does Datamimi cost?

Free plan: $0/month, 40 credits, no credit card required. Lite: $9/month, 400 credits. Starter: $24/month, 1,500 credits, up to 3 simultaneous files. Pro: $59/month, 5,000 credits with rollover. Team: $199/month, 20,000 credits, 5 users.

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DataMimi reads the file you actually have — merged cells, headers below row one, totals pasted at the bottom — and shows which rows and columns every number came from.

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