Quick Navigation

BINOM.INV Function

Excel 2010+

Summary

The BINOM.INV function returns the smallest integer k such that the cumulative binomial probability for k successes in n trials is greater than or equal to a specified threshold. Essential for binomial inverse distribution calculations in statistical analysis.

Syntax

BINOM.INV(trials, probability_s, alpha)

Parameters

Parameter	Type	Required	Description
trials	`Integer`	Yes	Number of independent Bernoulli trials (must be ≥ 0)
probability_s	`Number`	Yes	Probability of success on each trial (must be between 0 and 1)
alpha	`Number`	Yes	Threshold probability for cumulative distribution (must be between 0 and 1)

Using the BINOM.INV Function

BINOM.INV is crucial for statistical applications requiring inverse binomial calculations, such as determining minimum sample sizes, quality control pass/fail thresholds, and reliability testing scenarios where you need the smallest number of successes that meet a specific cumulative probability criterion.

Common BINOM.INV Examples

Quality Control Threshold

=BINOM.INV(6, 0.5, 0.75)

For 6 trials with 50% success probability, finds smallest successes where cumulative probability ≥ 75%. Returns 4.

Manufacturing Defect Analysis

=BINOM.INV(100, 0.02, 0.95)

Determines minimum acceptable defects in 100-unit batch with 2% defect rate to achieve 95% confidence.

Marketing Campaign Success

=BINOM.INV(20, 0.15, 0.80)

Finds minimum conversions needed from 20% response rate to reach 80% cumulative probability.

Frequently Asked Questions

Returns #NUM! error. Trials must be zero or positive integer.

No, returns #NUM! error. Must be between 0 and 1 inclusive.

Yes, Excel truncates non-integer trials to the next lower integer.

Common Errors and Solutions

#VALUE!

Cause: Any argument is non-numeric

Solution: Ensure all inputs are valid numbers

#NUM! (trials < 0)

Cause: Negative number of trials

Solution: Use zero or positive integer for trials

#NUM! (probability_s invalid)

Cause: Probability outside 0-1 range

Solution: Verify success probability is between 0 and 1

#NUM! (alpha invalid)

Cause: Criterion value outside 0-1 range

Solution: Alpha must be between 0 and 1 inclusive

Notes

Replaces legacy BINOMINV function
Trials parameter is truncated if not integer
Perfect for pass/fail testing scenarios
Returns integer value representing minimum successes

Compatibility

Available in: Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Excel for Microsoft 365, Excel for the web

Not available in: Excel 2007, Excel 2003, Earlier versions

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2010+