Days lost per exposure base. Based on OSHA / ILO. Results shown with the full formula so you can verify. Zero signup, zero tracking, zero data sent to a server — all calculation is client-side.
{
"rate": 18,
"base": 200000,
"formula": "(45 × 200,000) ÷ 500,000"
}Severity Rate measures average days lost per recordable incident. Complementary to TRIR (which counts frequency). Low severity means you're catching incidents before they become severe; high severity means your injuries are serious when they happen. Use both metrics together — a TRIR of 1 with severity of 100 is VERY different from TRIR of 1 with severity of 10.
OSHA convention uses 200,000-hour base; ILO/ISO uses 1,000,000. This calculator supports both.
Severity Rate = (Days Lost × Base) ÷ Hours WorkedOSHA / ILO
Days lost × base ÷ hours worked. OSHA base 200,000; ISO/ILO base 1,000,000.
Free for any website, blog, or course — MIT / CC BY 4.0. Attribution stays visible.
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