Combination Calculator
Calculate combinations (n choose r) for probability and odds.
🃏 Combinations: choosing r items from n, order doesn't matter. Lottery odds use this.
What Is This Tool?
A combination counts how many ways to choose r items from n, where order doesn't matter. Choosing 3 toppings from 10 is the same no matter which order you pick them — that's a combination.
The Formula
C(n,r) = n! / (r! × (n−r)!). For choosing 3 from 10: 10! / (3! × 7!) = 120.
Common Uses
- Lottery odds: Picking 6 from 49 = C(49,6) = 13,983,816
- Card games: A 5-card poker hand = C(52,5) = 2,598,960
- Team selection: Picking a 3-person committee from 10
- Inventory sampling: Quality control
Frequently Asked Questions
Combination vs permutation?
In combinations, order doesn't matter (a salad of {lettuce, tomato} equals {tomato, lettuce}). In permutations, order matters (a password "abc" differs from "cba"). Use the Permutation Calculator for ordered arrangements.
About the Combination Calculator
The Combination Calculator lets you figure out combination calculatorinstantly, without reaching for a spreadsheet or doing the math by hand. Whether you're planning a budget, checking a loan, or working through homework, the tool applies the correct formula behind the scenes and shows the result the moment you enter your numbers.
Unlike a static chart or table, this calculator adapts to your exact inputs. You can adjust any value and see the outcome update in real time, which makes it easy to compare scenarios — for example, "what if the rate were 1% lower?" or "what if I paid an extra $50 a month?"
How to Use This Tool
- Enter the main values the calculator asks for (for example, amount, rate, and time).
- Pick the right unit or option where the tool offers a choice.
- Read the result, which appears instantly below the inputs.
- Adjust any field to test a different scenario — the answer updates without a reload.
- Copy or note the result. Nothing is stored, so close the tab when you're done.
Why Use an Online Calculator?
Browser-based tools like this one have a few real advantages over installed software or manual methods:
- No installation. It opens instantly in any browser, on any operating system.
- Private by default. Everything runs locally, so your data stays on your device.
- Always up to date.There's nothing to update — you always get the latest version when you load the page.
- Free and unlimited. Use it as often as you like, with no account and no caps.
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