Standard deviation calculator
Enter your dataset values and instantly compute SD, variance, mean, and more — with a full step-by-step breakdown.
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SD Type
Results
Standard deviation
—
Population (σ)
Mean (x̄)
—
Average
Variance
—
σ² / s²
Count (n)
—
Data points
Sum
—
Σx
CV%
—
Coefficient of variation
Min
—
Minimum value
Max
—
Maximum value
Show step-by-step calculation
Formula reference
Population SD (σ)
σ = √[ Σ(xᵢ − μ)² / N ]
μ = Σxᵢ / N
μ = Σxᵢ / N
Sample SD (s)
s = √[ Σ(xᵢ − x̄)² / (n−1) ]
x̄ = Σxᵢ / n
x̄ = Σxᵢ / n
CV% (lab QC)
CV% = (SD / Mean) × 100
Lower CV% = better precision
Lower CV% = better precision
