There are many types of businesses which offer call centers to help aid their customers when purchasing or resolving an issue on a product. From airlines, to electronic companies to banks, functional call centers help answer the questions of the consumer so that they may resolve their issue and use their new product more effectively. Those operating call centers must ensure that they are running at an optimal performance level. To do this, they look at various statistics, such as the arrival rate. This is used to measure the rate of incoming calls.

Count the amount of incoming calls over the course of a day.

Multiply your chosen time unit to equal one day. For example, say you were calculating the arrival rate per minute. An hour has 60 minutes and a day has 24 hours. Therefore, the number of minutes in a day are 24 x 60 = 1,440. If you chose a per-second rate, the math would be 60 x 60 x 24 because a minute has 60 seconds. This equals 86,400 seconds in one day. If you chose a per-hour rate, it would simply be 24.

Divide the number of incoming calls by the seconds, minutes or hours per day. For example, say 10,000 calls came in over the course of one day and you want to calculate the arrival rate per minute. The equation would read:

10,000 calls / 1,440 = 6.94444 or the arrival rate is just about 7 calls per minute.