Online sample size calculator
Use our online sample size calculator to calculate accurate size and measurement values instantly.
Calculator
Estimate sample size using confidence level, margin of error, and proportion.
Formula: n = Z^2 x p x (1-p) / e^2
What each field means
- Confidence Level (%): Example: 95
- Margin of Error (%): Example: 5
- Estimated Proportion (0-1): Example: 0.5
Required Sample Size
Your result will appear here.
About Online sample size calculator
The Online sample size calculator helps you estimate sample size and statistics values quickly using consistent assumptions and practical calculation rules.
Formula Explanation
n = Z^2 x p x (1-p) / e^2
Inputs You Need
- Required measurement values relevant to this calculator
- Unit selection: Confidence Level (%), Margin of Error (%), Estimated Proportion (0-1)
- Optional tolerance, safety, or scenario values if applicable
Step-by-Step Usage
- Enter your known values in the calculator fields.
- Select units and options that match your scenario.
- Click Calculate to generate your output.
- Copy, save, or share the result for later reference.
Example
Run the tool with realistic values from your use case and compare the output against expected ranges for sample size and statistics calculations.
Method Sources
- https://www.calculator.net/sample-size-calculator.html
- https://en.wikipedia.org/wiki/Sample_size_determination
Frequently Asked Questions
Is this Online sample size calculator accurate?
Yes, when correct inputs and units are provided.
Which units does this calculator support?
This tool is optimized for Confidence Level (%), Margin of Error (%), Estimated Proportion (0-1).
Can I use this calculator on mobile?
Yes, the form is optimized for touch inputs and smaller screens.