In business, the term “units per transaction” means the average number of items sold for each purchase a customer makes. If you own or manage a retail store, units per transaction (also called items per sale) can be a very useful measure for evaluating sales trends. Calculating units per transaction is simple, but you can use this measure to track things like product sales over time, employee performance or to determine if a sales increase reflects customers buying more items or products that are more costly.

Choose the scope for calculating units per transaction that suits your needs. You may want to measure on a monthly basis, for instance. This will allow you to track changes from year to year and on a seasonal basis. Another way to measure units per transaction is by location so that you can identify market areas where customers tend to purchase different numbers of items when they shop. Still another approach is to track items per sale by employee as a measure of sales performance.

Collect and total the required data. You’ll need daily numbers of items sold and transactions. Depending on your specific objective, you may need to break the figures down by area or by employee. Add up all the items sold for the period for which you are calculating units per transaction. Do the same for the number of transactions.

Calculate units per transaction. Divide the units sold by the number of transactions. Suppose the purpose of measuring employee sales performance. Employee A made 30 sales with a total of 105 items. Employee B sold 105 items in 35 transactions. Employee A has sold 3.5 units per transaction and B 3.0 units per transaction.