Binomial Coefficient Calculator

Use our binomial coefficient calculator to calculate binomial coefficient values (n choose k) instantly. Includes how to calculate binomial coefficient, how to do binomial coefficient on calculator, how to put binomial coefficient in calculator, TI-84 steps, and binomial coefficient statistics context.

n (total items)
Enter a whole number (0 or higher).
k (chosen items)
Enter a whole number (0 ≤ k ≤ n).
Results
Binomial Coefficient C(n, k)
Computed as C(n, k) = n! / (k!(n−k)!).
C(n, k) = ?
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What is a Binomial Coefficient?

A binomial coefficient counts how many ways you can choose k items from n items without regard to order. It’s written as “n choose k” and commonly shown as C(n, k) or (n k).

Binomial coefficients appear in the binomial theorem, combinations, Pascal’s triangle, and binomial coefficient statistics (like binomial probability and combinatorics in statistics).

This binomial coefficient calculator computes C(n, k) quickly using the standard factorial-based formula.

Binomial Coefficient Formula

The binomial coefficient (n choose k) is a combinations formula. It can be computed using factorials or using an equivalent product form for efficiency.

Binomial coefficient =
C(n, k) = n! / (k!(n - k)!)

Valid for integers n ≥ 0 and 0 ≤ k ≤ n.

Symmetry =
C(n, k) = C(n, n - k)

Choosing k is the same as choosing what you leave out.

n
= Total number of items
k
= Number of items chosen
C(n, k)
= Number of combinations (binomial coefficient)
Calculate binomial coefficient example
C(5, 2) = 5! / (2!·3!) = 10

There are 10 ways to choose 2 items from 5.

Find binomial coefficient via symmetry
C(10, 8) = C(10, 2) = 45

Sometimes it’s easier to compute with the smaller k.

How to Use the Binomial Coefficient Calculator

  1. 1

    Enter n (the total number of items).

  2. 2

    Enter k (the number of items you choose).

  3. 3

    The calculator computes C(n, k) using the binomial coefficient formula.

  4. 4

    Use the result for combinations, binomial expansions, or binomial coefficient statistics problems.

Frequently Asked Questions

How to calculate binomial coefficient?

Use C(n, k) = n! / (k!(n−k)!).

What does a binomial coefficient mean in statistics?

It counts combinations and appears in binomial probability formulas and combinatorics used in statistics.

How to do binomial coefficient on calculator?

Many scientific calculators have an nCr function. Enter n, choose nCr, then enter k.

How to put binomial coefficient in calculator?

Use the combinations function nCr (sometimes under a PRB or probability menu). It computes n choose k.

How to calculate binomial coefficient on TI-84?

On TI-84, nCr is typically in the MATH menu under PRB. Enter n, select nCr, then enter k.

What if k is bigger than n?

For standard combinations, C(n, k) is defined as 0 when k > n, because you can’t choose more items than you have.

Is C(n, k) the same as permutations?

No. Binomial coefficients count combinations (order doesn’t matter). Permutations count ordered arrangements.