Mobile Engineering Tools
Crash Rate Calculator
Enter total sessions and crash sessions to compute crash-free rate, benchmark against industry standards, and estimate user impact.
Calculations run locally in your browserTool
Example — Representative default scenario — sessions 180000 · crashes 270.
Crash-free rate
99.700%
150 crashes in 50,000 sessions
vs iOS benchmark
⚠ Below 99.95%
Top 25% iOS apps
Daily crash rate
21/day
over 7 days
Monthly projection
643 crashes
30-day estimate
About this tool
Crash Rate Calculator
The Crash Rate Calculator computes crash-free session rate, benchmarks against industry standards, and estimates user impact and App Store rating risk.
• Calculate crash-free rate for a weekly quality report
• Assess whether current crash rate meets App Store quality thresholds
• Estimate user impact from current crash rate
• Set a crash rate SLO before a release quality gate
Affiliate disclosure
Uptime, incident, and on-call management. Better Stack provides status pages, incident management, and on-call scheduling for engineering teams.
View crashes with Better Stack
External site · Independent provider · We may receive a commission · Not a recommendation
FAQ
What does this tool tell you?
The Crash Rate Calculator computes crash-free session rate, benchmarks against industry standards, and estimates user impact and App Store rating risk.
What affects the result most?
Crash-free rate = 1 - (sessions_with_crash / total_sessions). Industry benchmark: >99.5% crash-free is good, >99.9% is excellent, <99% needs immediate attention. Session crash rate vs user crash rate: user rate usually lower — one user can have many sessions.
How should I use the result?
The calculation is deterministic — the same inputs always produce the same output — so the most useful workflow is to vary one input at a time and see which factor moves the result most. That tells you where to focus your attention before committing to a decision.