Dart Rate Calculator

Form

Results

DART Rate

0

Table of Contents

1

What is Dart Rate?

The DART rate is an occupational injury and illness incidence rate for cases involving days away from work, restricted work activity or job transfer. It places qualifying cases on a common base of 100 full-time-equivalent workers, making establishments with different workforce sizes easier to compare.

DART is a recordkeeping measure, not a count of every injury or a complete picture of workplace safety. Correct use starts with OSHA recordkeeping definitions and an accurate count from the establishment’s records. This calculator performs the rate arithmetic after those figures have been identified.

2

How to Use This Calculator

  1. Enter the number of qualifying DART cases for the period. For OSHA Form 300A, this corresponds to the total cases recorded in columns H and I of the OSHA 300 Log.
  2. Enter the total hours worked by all employees during the same period.
  3. Select Calculate. The calculator multiplies the case count by 200,000, divides by employee hours and displays two decimal places.

Use case count, not the number of days away or restricted days. Keep the numerator and denominator aligned to the same establishment and reporting period. Hours worked exclude non-work time such as vacation, sick leave and holidays even when employees are paid for that time, following OSHA’s Form 300A instructions.

3

Formula Used

DART rate = (number of DART cases × 200,000) ÷ total employee hours worked

The 200,000-hour base represents 100 employees working 40 hours per week for 50 weeks. It standardizes the result rather than describing your organization’s actual headcount.

Under OSHA’s recordkeeping framework, DART cases are recordable cases that involved days away from work, days of job restriction, or job transfer. A case with both days away and later restricted duty is still one case in the numerator. The number of affected days belongs elsewhere in the record and is not substituted for the case count in this formula.

4

Variables Explained

Values used to calculate a DART incidence rate
ValueMeaningRecordkeeping note
DART casesRecordable cases involving days away, restriction or transferFor Form 300A, use cases corresponding to OSHA 300 Log columns H and I, not a sum of lost days.
Total hours workedHours actually worked by all employees in the periodUse the same establishment and period as the case count.
200,000Standard incidence-rate baseEquivalent to 100 workers at 40 hours a week for 50 weeks.
DART rateQualifying cases per 100 full-time-equivalent workersThe calculator rounds this rate to two decimal places.
5

Worked Example

An establishment records 7 DART cases and 350,000 total employee hours worked during the year.

  1. Multiply cases by the standard base: 7 × 200,000 = 1,400,000.
  2. Divide by hours worked: 1,400,000 ÷ 350,000 = 4.
  3. At two decimal places, the displayed DART rate is 4.00.

This means the establishment experienced the equivalent of 4 DART cases per 100 full-time workers for that period. It does not mean exactly four employees were affected for every group of 100 actually employed. The standardized denominator permits comparison even when staffing levels and work hours differ.

As a cross-check, entering 4 cases and 400,000 hours gives (4 × 200,000) ÷ 400,000 = 2.00. Doubling hours while holding cases constant halves the rate; doubling cases while holding hours constant doubles it.

6

Why Use This Calculator?

Read the result as a standardized incidence rate for the stated period. A rate of 4.00 represents four qualifying cases per 100 full-time-equivalent workers, based on the 200,000-hour convention.

Comparisons need context. Establishments should use the same definitions, period and workforce scope. Industry, establishment size, work performed and reporting practices can affect the comparison. A lower rate does not prove that hazards are controlled, and a higher rate does not identify the causes or severity of the cases. Review the underlying logs, incident details, exposure hours and prevention controls.

For formal submissions or compliance decisions, follow the OSHA regulations, instructions and any applicable state-plan requirements. This arithmetic tool does not decide whether a case is recordable or whether days qualify as restriction, transfer or days away. Those classifications must be made first from the relevant recordkeeping rules.

7

Common Mistakes

    • Counting days instead of cases: ten restricted days from one case contribute one qualifying case, not ten cases, to the numerator.
    • Using total paid hours: OSHA instructions ask for hours actually worked, excluding vacation, sick leave, holidays and other non-work time.
    • Mixing periods: annual cases divided by one quarter’s hours produce a meaningless rate.
    • Using headcount as the denominator: the formula requires employee hours worked, then applies the 200,000-hour standard base.
    • Double-counting one case: a case can involve days away and restricted duty but should not be counted twice in the DART numerator.
    • Entering zero hours: division by zero is undefined, so the calculator requires a positive hours-worked value.
    • Treating DART as a complete safety score: the rate omits important information about hazards, near misses, severity and preventive work.
8

Frequently Asked Questions

What does DART stand for?

It refers to recordable cases involving days away from work, restricted work activity or job transfer. The rate uses a standardized hours base so establishments of different sizes can be compared more consistently.

Why does the formula use 200,000 hours?

OSHA’s base represents 100 workers working 40 hours each week for 50 weeks. It converts the establishment’s case and hours figures to a common full-time-equivalent scale.

Do I enter the number of days away from work?

No. Enter the number of qualifying cases. One case may involve several days away or restricted duty, but it remains one case in the numerator. Days are recorded separately.

Which employee hours should be included?

Use hours actually worked by all employees included in the establishment’s records for the same reporting period. OSHA’s Form 300A instructions exclude vacation, sick leave, holidays and other hours not worked.

Can I compare our DART rate with another company?

You can compare rates cautiously when the definitions, periods and establishment scope are consistent. Industry, job mix, hours, size and reporting practices also matter, so the rate should be reviewed alongside the underlying safety information.

9

Sources & References

Mini Calculator provides online calculators for multiple niches including mathematical, financial, Health, informative, Chemistry, physics, statistics, and conversions. You can use any calculator for free without any limits.