Dart Rate Calculator - OSHA Case Rate

A dart rate calculator turns OSHA DART cases and employee hours worked into a workplace injury and illness incidence rate. Safety managers, HR teams, operations leaders, and contractor prequalification reviewers use it to prepare OSHA 300A summaries, compare establishments, review contractor safety submissions, and track whether serious recordable cases are moving in the same direction as total recordables.

• • OSHA log review: Check the rate after the OSHA 300 Log and 300A summary are prepared, using the same case counts and hours.
• • Contractor qualification: Convert submitted DART cases and work hours into a rate that can be compared with a site or procurement standard.
• • Year-over-year safety review: Compare the current period with a prior-year rate while keeping the same 200,000-hour base.
• • Recordable case mix: See what share of all recordable cases involved days away, restriction, or transfer.

DART stands for days away, restricted, or transferred. The numerator is not every workplace injury or illness. It is the subset of recordable cases that led to at least one day away from work, restricted work activity, or transfer to another job. That distinction matters because a company can have a moderate total recordable rate but a higher share of serious cases.

Use the result as a rate and audit prompt, not as a legal conclusion. The calculator assumes your case classification is already correct. If a case is disputed, involves medical restrictions, or has uncertain work relatedness, resolve the recordkeeping question before relying on the number.

When safety trends are reviewed with turnover patterns, the Attrition Rate Calculator helps compare workforce exits against the same reporting period.

The calculation uses OSHA's standard incidence-rate structure. It normalizes actual case counts to the hours that 100 full-time workers would commonly work in one year.

• DART cases: Recordable cases with days away from work, restricted work activity, or job transfer.
• Employee hours worked: Total hours worked by all employees in the same period as the cases.
• 200,000: The base for 100 full-time equivalent workers working 40 hours per week for 50 weeks.
• TCIR: Total recordable case incidence rate, calculated with total recordable cases instead of only DART cases.

Enter DART cases from the same establishment and period as the employee hours. Mixing one site's cases with another site's hours changes the denominator and can make the result unusable. The optional comparison rate is not part of the OSHA formula; it only shows the gap between your calculated rate and a benchmark you supply.

The tool also calculates TCIR and DART share. TCIR uses total recordable cases in the numerator. DART share divides DART cases by total recordable cases, which helps show whether severe outcomes are concentrated inside the recordable case total.

According to OSHA Recordkeeping Policies and Procedures Manual, the DART rate includes cases involving days away from work, restricted work activity, and transfers to another job and is calculated as (N/EH) x 200,000.

If the hours denominator needs a staffing-capacity check, the Full-Time Equivalent Calculator converts work hours into full-time equivalent staffing assumptions.

These terms decide whether the number is useful. Review them before comparing departments, job sites, contractors, or calendar years.

A high rate can come from a small number of cases when employee hours are low. That is why small establishments and short reporting periods can produce sharp swings. For management review, keep the numerator, denominator, and review window visible next to the rate.

The comparison rate should come from a source you can defend, such as a published BLS industry table, a prior OSHA 300A summary, a contractor requirement, or an internal site target. Do not compare a monthly site result with an annual corporate result without explaining the period difference.

For another workplace absence metric built from events and days, the Bradford Factor Calculator shows how repeated absence spells can change an HR review score.

Use the dart rate calculator after your case list and work-hour totals have already been reconciled.

1. 1 Enter DART cases: Use only cases with days away, restricted work, or job transfer for the period being reviewed.
2. 2 Enter total recordables: Add all OSHA-recordable cases from the same period so the calculator can show TCIR and DART share.
3. 3 Enter hours worked: Use employee hours worked for the same establishment and period as the case counts.
4. 4 Add a comparison rate: Use a prior-year, site, contractor, or published industry rate if you have one.
5. 5 Review the outputs together: Look at DART rate, TCIR, DART share, and comparison gap before drawing conclusions.

For a contractor review, enter the contractor's DART cases, total recordables, and project hours from its submitted safety packet. If the DART rate is above your comparison rate but TCIR is close, the discussion should focus on case severity and restricted-duty outcomes, not only the total number of recordables.

When project records separate billable and nonbillable labor, the Billable Hours Calculator can help reconcile hour categories before safety rates are reviewed.

A consistent DART worksheet makes safety-rate discussions easier to audit and less dependent on spreadsheet habits.

• • Standardized rate review: The same 200,000-hour base is applied every time, so site and year comparisons use the same calculation.
• • Clear severity signal: DART share shows whether total recordables are weighted toward cases that affected work status.
• • Better contractor questions: A comparison gap gives procurement teams a focused starting point for asking about controls, exposure hours, and recent cases.
• • Cleaner management reporting: The output separates DART rate, TCIR, and case mix so each metric can be discussed without blending them.
• • Fast sensitivity checks: Changing hours or case counts shows how a corrected log entry or revised payroll-hour total affects the rate.

The benefit is strongest when the organization keeps the supporting records with the calculation. Save the DART case list, recordable case total, hours-worked source, reporting period, and comparison-rate source. Without that backup, a precise-looking rate can still be hard to defend.

The calculator can also expose data-quality issues. If DART cases exceed total recordables, if hours are unusually low, or if the comparison rate comes from a different industry, the result should be paused until the source data is corrected.

The formula is short, but several inputs and context choices can change the meaning of the result.

• • This calculator does not decide whether an injury or illness is OSHA-recordable. It only calculates rates from the case counts you enter.
• • The comparison gap is only as useful as the benchmark supplied. A rate from a different industry, year, or establishment size can mislead.
• • The calculator does not replace legal, safety, or recordkeeping advice for disputed cases, inspections, citations, or reporting obligations.

When comparing against published data, use the closest industry and establishment context available. A single corporate average can hide very different risk profiles across field work, warehouses, laboratories, offices, and construction sites. The calculator leaves benchmark choice to you because OSHA and BLS data should be matched to the actual operation being reviewed.

DART rate should be reviewed with leading indicators and corrective-action status. A falling rate may reflect improved controls, but it can also reflect lower exposure hours, delayed case classification, or under-recording. Keep the supporting log and hours source attached to the result.

According to BLS Occupational Safety and Health Definitions, an incidence rate equals (N/EH) x 200,000, where 200,000 represents 100 full-time equivalent workers working 40 hours per week for 50 weeks.

According to OSHA Recordkeeping Resources, the OSHA 300 Log has separate check boxes for days away cases and job transfer or restriction cases, and those columns can be added to calculate a combined days-away-and-restricted incidence rate.

When safety reviews also track missed work time, the Absence Percentage Calculator helps compare absence days or hours with the same reporting period used for DART.