Biostatistics Tool · v4.3
Sample Size
Calculator
Community Medicine & Public Health · KSHEMA · Dr. Pawan Kumar B
☀️
Advanced
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Sample Size Calculation Sheet
📊
Single Proportion
Prevalence / Cross-sec.
⚖️
Two Proportions
Case-control / RCT
📈
Single Mean
Continuous outcome
🔬
Two Means
Group comparison
🩺
Diagnostic Study
Sn / Sp · Buderer
🔗
Cluster Sampling
DEFF integrated
🤝
Kappa / Agreement
Inter-rater reliability
Result
Minimum Sample Size
—
participants
One-sided test (uses z
α
not z
α/2
)
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Breakdown
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Finite Population Correction
FPC
Apply FPC
off
Population size (N)
N
Known finite population
FPC-adjusted n
—
Cluster Design Effect
DEFF
Apply DEFF
off
Cluster size (m)
m
Subjects per cluster
ICC (ρ)
ρ
0.05
Community ≈ 0.02–0.10
DEFF-adjusted n
—
OR / RR → P₁ Converter
OR/RR
Derive P₁ from OR or RR for Two Proportions
Measure
Odds Ratio (OR)
Risk Ratio (RR)
OR / RR value
θ
Control P₂ (%)
P₂
Derived P₁
—
⇒ Auto-fill into Two Proportions tab
📊 Comparative Table
🧪 Pilot Sizing
📚 References
🎯 Multi-Outcome
🧭 Formula Guide
💾 Presets
🖨 Export PDF
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Comparative Table
Vary parameter
Matrix: also vary
— none (list mode) —
⊞ Matrix
Pilot Study Sizing
Estimate parameters before the main study
Prevalence Estimation Pilot
Desired precision (d)
10%
α
5%
10%
—
Assumes P=50% (worst case)
SD Estimation Pilot
Desired CV of SD estimate
15%
—
Precision-based; minimum n ≥ 30
10% of Main Study
Standard: pilot = 10% of main n, minimum 30
—
Based on current main study n
Feasibility Pilot
Logistics / instrument testing — not powered for significance
12–30
CONSORT/SPIRIT recommendation
Study References
Multi-Outcome Sample Size
Picks largest n across all outcomes
Significance (α)
5% (z=1.96)
1% (z=2.576)
10% (z=1.645)
Power (1−β)
80%
90%
85%
95%
+ Add Outcome
Formula Guide
Not sure which formula to use? Start here
Saved Presets
Save and reload study configurations
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Sensitivity Analysis
click to apply
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