Formula and method
This calculator uses the values you enter and applies the calculation immediately in your browser. The main output formulas are:
- Probability:
(() => { if(k>n) return 0; let f=(x)=>{let r=1;for(let i=2;i<=x;i++) r*=i; return r;}; const c = f(n)/(f(k)*f(n-k)); return c*Math.pow(p,k)*Math.pow(1-p,n-k); })()
Some formulas are undefined for certain input combinations, such as division by zero, equal x-values in a slope calculation, or logarithms of non-positive numbers. In those cases the live tool reports that the result is undefined instead of displaying Infinity or NaN.
Examples
- Example: with Number of trials = 10, Number of successes = 3, Probability of success = 0.5, this calculator returns Probability = 0.11719.
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Frequently asked questions
Is Binomial Probability Calculator free to use?
Yes. Binomial Probability Calculator is completely free, has no usage limit, and does not require an account, email, or API key.
Does Binomial Probability Calculator store or upload my data?
No. Binomial Probability Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.
How accurate is Binomial Probability Calculator?
Binomial Probability 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 Binomial Probability Calculator on my own website?
Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Binomial Probability Calculator to your own blog post or page.
SEO and sharing notes
This page has a single clean canonical URL, descriptive metadata, breadcrumb structured data, and internal links to related tools. Supported calculators and converters can also copy a prefilled share link without changing the canonical index URL.