IT & Developers
Bcrypt Cost Calculator - Find optimal bcrypt cost factor for your system
Find optimal bcrypt cost factor for your system
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What is cost factor?
Number of iterations = 2^cost. Higher cost = slower hash = more secure but slower logins.
What cost should I use?
Target ~250ms hash time. In 2024, cost 12-14 is typical for modern servers.
Why not maximum cost?
Too slow impacts user experience and can enable DoS attacks via login attempts.
Related tools
About this tool
Inputs
- Target Hash Time
- Test Password
- Cost
Results
- Recommended Cost Factor
- Estimated Hash Time
- Cost Factor Benchmarks
- Brute Force Time (6 char)
- Security Notes
When precision matters, guesswork falls short. The Bcrypt Cost Calculator applies the correct formula to the values you enter and returns a clear result. All you need to supply is target hash time, test password and cost. From there, the tool determines recommended cost factor, estimated hash time, cost factor benchmarks and other key metrics. Output format follows the relevant specification, so it integrates directly with other tools and systems.
Correct data handling prevents corruption, security vulnerabilities, and interoperability issues. Test edge cases: empty strings, Unicode characters, very long inputs, and special characters. From students to professionals, anyone who needs to find optimal bcrypt cost factor for your system benefits from getting an instant, verifiable answer. Even small deviations from a standard — a missing padding character, a wrong byte order — can break systems silently. Run the calculation with your best-case and worst-case assumptions to bracket the likely outcome. Always specify the character encoding (usually UTF-8) before encoding or hashing text.