Time-Weighted Average Calculator

Calculate Time-Weighted Average



Formula

The formula to calculate the Time-Weighted Average (TWA) is:

\[ \text{TWA} = \frac{\sum (C_i \times T_i)}{\sum T_i} \]

Where:

What is Time-Weighted Average?

The Time-Weighted Average (TWA) is a method of calculating the average exposure to a substance over a specified period, taking into account both the concentration levels and the time spent at each level. It is commonly used in occupational health to assess exposure to hazardous substances[^1^].

Example Calculation

Consider an example where the concentrations and durations are:

Using the formula to calculate the Time-Weighted Average:

\[ \text{TWA} = \frac{(50 \times 2) + (100 \times 3) + (150 \times 5)}{2 + 3 + 5} = \frac{100 + 300 + 750}{10} = 115 \]

This means that the time-weighted average for this example is 115.