Coefficient of variation calculator
CV = (SD / mean) × 100%. Compare spread across different scales
Enter survey data
Option 1: enter a sample of numbers. Option 2: enter mean and standard deviation.
Assumptions and limitations
- CV = (σ / μ) × 100%, where σ = standard deviation, μ = mean. For sample: SD with n (unbiased estimate).
- When mean is close to zero, CV is meaningless — the calculator will show a warning.
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Coefficient of variation
Why use CV
To compare spread of variables on different scales: e.g. variation in revenue (in currency) vs variation in market share (%). SD has different units; CV is dimensionless %.
Interpretation
CV < 15% — low variability; 15–30% — moderate; > 30% — high. Norms vary by field: biology and economics often use different thresholds.
Limitations
Meaningful only for positive mean (or when interpreting |μ|). For zero or negative mean, CV is not used.
When to use
Comparing stability of metrics (e.g. NPS by region vs conversion by channel), assessing risk and spread in reports.
Coefficient of variation calculation examples
1 Revenue
2 Conversion
3 NPS by region (sample)
4 Stable metric
5 Comparing two channels
6 Response time (seconds)
Interpreting CV
Norms depend on industry and metric; biology and economics often use different thresholds. CV is meaningful only for positive mean.
Frequently asked questions about coefficient of variation
What is the coefficient of variation?
Why use CV instead of SD?
When is CV not suitable?
What are typical CV norms?
How to enter data?
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In SurveyNinja, NPS, CSAT and more are calculated automatically. Create a survey in 5 minutes and get real-time analytics.
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