A combination lock with n numbers on the dial and k positions has n^k total combinations (with repetition) or n!/(n−k)! without. A standard 40-number, 3-position lock has 40³ = 64,000 combinations. At 10 tries/minute, cracking takes ~107 hours — but real locks have exploitable tolerances.
How to Use
Configure your lock:
- Dial size: Numbers on the dial
- Positions: How many numbers
- Repetition: Can numbers repeat?
Security Analysis
- 3-digit (10): 1,000 combos, ~1.7 hours
- 4-digit (10): 10,000 combos, ~17 hours
- 3-dial (40): 64,000 combos, ~107 hours
Mathematics
With repetition: n^k. Without: n!/(n−k)!. The formula changes based on whether order matters and whether repeats are allowed.
Step-by-Step Instructions
- 1Set the dial size.
- 2Set number of positions.
- 3Toggle repetition allowed.
- 4View total combinations.
- 5Check crack time estimates.