📖 Overview
This sample size calculator estimates required n for a proportion study under desired confidence and precision.
🧪 Example Scenarios
Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.
| Input | Base Case | Higher Pressure Case |
|---|---|---|
| Confidence Code (1=90 2=95 3=99) | 2 | 2.3 |
| Margin Of Error (%) | 5 | 6 |
| Estimated Proportion (%) | 50 | 60 |
| Population Size (0 for large/infinite) | 0 | 0 |
⚙️ How It Works
This calculator applies a direct math model based on the inputs above.
💡This calculator is scenario-based. Better input quality leads to better decision quality.
Quick Reference
| Input | Example Value |
|---|---|
| Confidence Code (1=90 2=95 3=99) | 2 |
| Margin Of Error (%) | 5 |
| Estimated Proportion (%) | 50 |
| Population Size (0 for large/infinite) | 0 |
When To Use This
- Use this tool when you need a fast decision during active planning or execution.
- Use this before committing money, time, or tradeoffs that are hard to reverse.
- Use this to compare options using the same assumptions across scenarios.
Edge Cases To Watch
- Results can be misleading if key inputs are missing, stale, or unrealistic.
- Very small or very large values may amplify rounding effects and interpretation risk.
- If assumptions change mid-decision, recalculate before acting.
Practical Tips
💡 Validate units before comparing scenarios.
💡 Run multiple values to understand sensitivity.
💡 Use outputs as estimates, not guarantees.
Frequently Asked Questions
❓ Is this output exact?
It is a fast estimate based on provided inputs and model assumptions.
❓ Can I compare different scenarios?
Yes, this tool is designed for quick side-by-side checks.