The Ultimate Guide: How Many Combinations on a 4-Digit Lock?

If you’re interested in smart home security, then you may be familiar with the idea of using a 4-digit lock to secure your home. But have you ever wondered how many possible combinations there are for a 4-digit lock? In this guide, we’ll explore the math behind combinations and permutations, provide some tips for choosing secure passwords, and discuss how to apply this knowledge to protect your home.

The Ultimate Guide: How Many Combinations on a 4-Digit Lock?

What is a Combination?

A combination is an arrangement of objects in which order does not matter. For example, if we have three numbers (1, 2, and 3) and want to find all possible combinations of two numbers without repeating any number twice (e.g., [1,2] but not [1,1]), we can use the following formula:

n! / r!(n-r)!

where n is the total number of objects (in this case three), r is the number of objects being chosen at once (in this case two), and ! denotes factorial notation (i.e., multiplying each integer from n down to one).

Plugging these values into our formula gives us:

3! / 2!(3-2)! = 3

So there are three possible combinations: [1,2], [1,3], and [2,3].

How Many Combinations Are Possible On A Four-Digit Lock?

To calculate the total number of possible combinations for a four-digit lock where digits cannot repeat themselves in any given combination e.g.(1234 OK -1125 NO), we need to use permutation instead of combination because order matters. Using our previous formula with four digits yields:

10 * 9 * 8 *7=5040

So there are over five thousand different possible permutations or combinations that could represent your unique code.

Tips for Choosing Secure Passwords

While 5,040 possible combinations may sound like a lot, there is always the risk of someone guessing your code or using trial and error to crack it. To avoid this situation, consider creating a secure password by following these tips:

  • Avoid common codes such as “1234”, “0000,” or “1111”
  • Do not use easily guessable personal information such as birth dates or phone numbers
  • Use a mix of upper and lowercase letters along with numbers and special characters
  • Make sure the password is at least eight digits long

By implementing these guidelines for setting passwords on your smart locks, you will substantially increase their level of security.


In conclusion, understanding how many combinations are available in a 4-digit lock can greatly improve our ability to keep our homes secure from potential intruders. With over five thousand different permutations available for four-digit codes that do not repeat values within them (e.g., no [1,1]), we have enough options to create highly unique codes that deter unauthorized personnel from entering our homes even if they know which format was used. Combining knowledge of mathematical formulas with best practices for choosing passwords allows us to safeguard ourselves effectively against unwanted visitors by creating uncrackable codes for our smart home devices.


Sure! Here are three popular FAQs with answers for “The Ultimate Guide: How Many Combinations on a 4-Digit Lock?”.

Q: Can someone guess the combination of a 4-digit lock if they try enough times?
A: While it is technically possible to guess the combination of a 4-digit lock, it would take an average of 5,000 attempts to do so. Furthermore, many locks have mechanisms that will prevent someone from trying too many combinations in quick succession.

Q: How long does it take to crack a 4-digit lock using random guessing?
A: If someone were attempting to unlock a four-digit combination padlock by randomly guessing numbers (without any knowledge of what the actual code was), it could take up to ten hours – assuming one second per attempt and no restrictions on how many attempts can be made).

Q: Are all four-digit locks equally secure?
A: No, not all four-digit locks are created equal in terms of security. Some models may offer more complex combinations or additional features such as anti-tampering mechanisms or pick-resistant designs that make them less vulnerable to hacking or manipulation than others. When choosing a lock, look for features like these and consider your specific needs and level of risk tolerance when selecting a product