Calculateur de Margin Of Error
Estimate margin of error for a proportion from sample size and confidence z-score.
Formula and method
This calculator computes Margin of error directly in your browser without sending data to an external server.
Mathematical formula
- Margin of error:
p>1 ? NaN : z × √(p × (1-p) ÷ n) × 100
Variables and parameters
- Z-score (z): default value 1.96.
- Proportion (p): default value 0.5.
- Sample size (n): default value 1000.
Some formulas are undefined for certain input combinations (such as division by zero or logarithms of non-positive numbers). In those cases the live tool displays an alert instead of NaN.
Embed this tool
Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.
Frequently asked questions
What equation and variables does Margin Of Error Calculator use?
Margin Of Error Calculator evaluates outputs such as <strong>Margin of error</strong> based on inputs including Z-score, Proportion, Sample size. Check the Mathematical Method section for the explicit formula.
What happens if I enter invalid or zero values into Margin Of Error Calculator?
If an input combination is mathematically undefined (such as division by zero or negative square roots), SpecWhale alerts you gracefully rather than returning invalid NaN outputs.
Are my calculations in Margin Of Error Calculator saved or private?
All calculations are 100% private and run locally in your Web browser. Your numbers are never uploaded to any server, but can be saved locally to your device or exported as CSV/JSON.
Is Margin Of Error Calculator free to use?
Yes. Margin Of Error Calculator is completely free, has no usage limit, and does not require an account, email, or API key.
Does Margin Of Error Calculator store or upload my data?
No. Margin Of Error Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.
How accurate is Margin Of Error Calculator?
Margin Of Error Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.
Can I embed Margin Of Error Calculator on my own website?
Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Margin Of Error Calculator to your own blog post or page.