What is the Dart Rate Calculation

Understanding the DART Rate Calculation for OSHA Safety Reporting

For businesses committed to maintaining a safe workplace, tracking incident metrics is crucial not just for compliance with the Occupational Safety and Health Administration (OSHA), but for understanding the true health of your safety culture. One of the most critical metrics used for benchmarking workplace safety is the DART Rate.

DART stands for Days Away, Restricted, or Transferred. The DART rate calculation measures the number of recordable incidents per 100 full-time employees that resulted in days away from work, restricted work activity, or a job transfer due to a work-related injury or illness.

Why is the DART Rate Important?

Unlike the Total Recordable Incident Rate (TRIR), which counts all recordable incidents regardless of severity, the DART rate specifically isolates incidents that were severe enough to impact an employee's ability to perform their regular job duties. A high DART rate indicates that workplace injuries are not just occurring, but they are severe enough to cause lost time or significant operational disruption.

Many industries use DART rates to benchmark safety performance against competitors. Furthermore, OSHA often uses high DART rates as a trigger for workplace inspections.

The DART Rate Formula

The standard formula used by OSHA to calculate the DART rate is straightforward. It standardizes the data to represent the equivalent of 100 full-time employees working for one year.

DART Rate = (N x 200,000) / EH

• N (Number of DART Incidents): The total number of recordable injuries and illnesses that resulted in Days Away from work, Restricted work activity, or Job Transfer during the period covered.
• EH (Employee Hours): The total number of hours worked by all employees during the same time period.
• 200,000: This represents the base figure for 100 equivalent full-time workers (working 40 hours per week, 50 weeks per year).

Example Calculation

Let's imagine a manufacturing company wants to calculate its DART rate for the previous calendar year. Their records show:

• They had 6 separate incidents where an employee either missed work days, was placed on restricted duty, or transferred jobs due to injury.
• The total hours worked by all employees in the facility for the year was 450,000 hours.

The calculation would be: (6 x 200,000) / 450,000 = 1,200,000 / 450,000 = 2.67.

This means for every 100 full-time employees, the company experienced 2.67 DART-related incidents.

OSHA DART Rate Calculator

Use the calculator below to determine your organization's DART rate. Enter your total number of DART incidents and total employee hours worked for the specific reporting period (usually one calendar year).

DART Rate Calculator

(Cases with days away, restricted, or transferred)

(Total hours for all employees in period)

Your Calculated DART Rate:

Incidents per 100 full-time equivalent employees.

function calculateDARTRate() { var incidentsInput = document.getElementById('dartIncidents'); var hoursInput = document.getElementById('totalHoursWorked'); var resultDiv = document.getElementById('dartResultOutput'); var resultValueDiv = document.getElementById('dartRateValue'); var incidents = parseFloat(incidentsInput.value); var hours = parseFloat(hoursInput.value); var constantMultiplier = 200000; // Reset error styling incidentsInput.style.borderColor = "#ccc"; hoursInput.style.borderColor = "#ccc"; // Validation var isValid = true; if (isNaN(incidents) || incidents < 0) { incidentsInput.style.borderColor = "red"; isValid = false; } if (isNaN(hours) || hours <= 0) { hoursInput.style.borderColor = "red"; isValid = false; } if (!isValid) { resultDiv.style.display = "none"; alert("Please enter valid non-negative incidents and positive total hours worked."); return; } // The complete calculation logic var dartRate = (incidents * constantMultiplier) / hours; // Display results rounded to two decimal places resultValueDiv.textContent = dartRate.toFixed(2); resultDiv.style.display = "block"; }

Interpreting Your Results

Once you have your DART rate, the next step is comparing it. You should compare your current rate to your rates from previous years to identify trends. Is your safety performance improving or declining?

Additionally, you should compare your DART rate to the industry average. The Bureau of Labor Statistics (BLS) publishes annual data on DART rates by industry (using NAICS codes). If your rate is significantly higher than your industry average, it indicates a need to review your safety protocols, training programs, and hazard assessments to reduce severe workplace incidents.