title: How to aggregate returns in an excel UDF using the product formula
body: <p>I am trying to put the below formula into a UDF so that I can get a cumulative return when I aggregate monthly returns.</p>
  
  <p>In excel the formula has to be recognized as an array so when I type it in I press <kbd>Ctrl</kbd> + <kbd>Shift</kbd> + <kbd>Enter</kbd> to get the <code>{}</code> brackets around the formula. </p>
  
  <p>Does anyone know how to do this? </p>
  
  <p>I want to be able to just type in <code>returns_calc()</code> and select the range that would fit into the returns variable below.</p>
  
  <pre><code>{=(PRODUCT(1+returns/100)-1)*100}
  </code></pre>