What happens if the cost factor is set too high?

Setting the cost factor too high (e.g. 15 or 16) can cause each password verification to take multiple seconds, creating a severe CPU bottleneck and exposing the server to denial-of-service (DoS) risks.

Updated: August 2026 • Verified v1.2

Bcrypt Work Factor & Latency Security Calculator

Developer ToolsHigh Usage

Local Browser Execution: Your input is processed locally in your browser and is not sent to UTL servers.

Bcrypt Iterations = 2^(Cost); Latency[ms] = Base_Latency * 2^(Cost - 10)

Was this calculation helpful?

Understanding Your Results

Calculates key derivation rounds, estimated server latency in milliseconds, maximum hash verifications per CPU core per second, and provides an OWASP security evaluation.

Practical Guidance & Next Steps

OWASP recommends a minimum work factor of 10, with 12 being the optimal balance between brute-force protection and server latency.

What is this?

A cryptographic security utility that models Bcrypt key derivation cost factors and CPU latency.

How does it work?

1. Adjust the Bcrypt cost factor slider (4 to 16). 2. View total key derivation rounds, estimated latency per hash, and single-core throughput. 3. Check OWASP compliance status and copy benchmark summary.

Why use it?

Helps backend teams tune password hashing parameters to prevent brute-force attacks without degrading login responsiveness.

Technical Scope & Calculation Limitations

Latency estimates are based on standard server CPU benchmarks.

Frequently Asked Questions

The cost factor (work factor) determines how many key expansion iterations ($2^{\text{cost}}$) Bcrypt performs to hash a password, making offline GPU brute-force attacks computationally expensive.

Windows Desktop & Widget Options