DART Rate Calculator

The DART rate calculator measures cases involving days away from work, restricted duty, or job transfer per 200,000 hours worked. It applies OSHA’s general incidence-rate equation to the DART case count entered by the user: multiply the count by 200,000 and divide by total hours worked before rounding for display. The cited OSHA interpretation supplies the general equation and normalization, not a separate DART-specific rule or classification.

DART is narrower than total recordable incident rate. A first-aid-only event is not DART. A recordable case that requires medical treatment but no days away, restriction, or transfer may affect TRIR without affecting DART. A case with days away or restricted work can affect both. That distinction matters because DART cases usually interfere more directly with scheduling, staffing, overtime, and job continuity.

What to enter

Enter total DART incidents for the period you are reviewing. Incidents must be a whole-number count. The period can be a calendar year, quarter, project, plant shutdown, or contract term, but the hours must match the same period. Enter total hours worked by employees during that period. The calculator requires hours worked to be greater than zero and incidents to be zero or higher.

Formula

The calculator applies OSHA’s general incidence-rate equation to the entered DART case count:

$\text{DART rate} = \frac{\text{DART incidents} \times 200{,}000}{\text{hours worked}}$

The 200,000 factor equals 100 full-time employees times 2,000 work hours per year. It makes a raw count comparable across operations with different sizes. A company with two DART cases in 50,000 hours has a higher rate than a company with two DART cases in 250,000 hours because the first company had less exposure time.

Example: calculating a dart throwing rate

Use the form defaults: 8 total DART incidents and 400,000 total hours worked.

$\text{DART rate} = \frac{8 \times 200{,}000}{400{,}000} = 4.00$

If the same 8 cases occurred over 800,000 hours, the rate would be 2.00. The underlying number of people hurt did not change, but the rate is lower because the workforce performed twice as many hours. If 12 cases occurred over 300,000 hours, the rate would be 8.00.

How DART is used operationally

DART is a bridge between safety performance and labor planning. Cases with days away, restrictions, or job transfers can create replacement shifts, overtime, supervisor follow-up, retraining, job modifications, and medical-case management. A manager reviewing DART may also need the man-hours calculator to understand exposure hours for a project, the labor cost calculator to estimate payroll impact, and the off-day calculator when scheduling paid leave separately from injury-related time away. For a broader safety dashboard, compare this page with the TRIR calculator.

Customers and prime contractors sometimes ask for DART rates during prequalification because the metric highlights cases that changed the employee’s ability to work normally. Internally, it helps safety teams prioritize controls that prevent serious disruptions, not just minor recordables. Finance teams may pair DART with workers’ compensation claims, overtime spending, and production delays, while HR teams may use it to review modified-duty processes.

Caveats before reporting the number

The calculator does not classify cases. It assumes the incidents entered are already identified as DART cases under the rules that apply to your recordkeeping. It also does not verify whether hours exclude vacation, holidays, sick leave, or other nonworked paid time. Include only exposure hours for the population represented by the incident count.

Industry risk matters: warehousing, construction, manufacturing, health care, and office work have different exposure profiles. This calculator supplies no benchmark or compliance threshold. Review a DART rate with properly matched official industry data, job type, hours, workforce size, case severity, and reporting quality.

Sources

• OSHA, “Clarification on how the formula is used by OSHA to calculate incident rates” — standard interpretation dated August 23, 2016, paragraph beginning “Incidence rates can be used”; states (number of injuries and illnesses × 200,000) / employee hours worked and explains the 100-employees × 40-hours × 50-weeks normalization. This calculator applies that general incidence-rate equation to the user-entered DART case count; the source is not presented as a DART-specific classification.
• Calculation scope: The equations and assumptions described above are applied only to values entered in the form. No live rates, prices, tax rules, lender terms, or accounting classifications are fetched. Results are user scenarios, not quotes or prescribed classifications.