title: Why is the height size of a renderObject for a Text Widget bigger than the fontSize
body: <p>Consider having this simple Text Widget:</p>
  
  <pre><code>Text(
      product.name,
      style: TextStyle(fontSize: 16)
  )
  </code></pre>
  
  <p>When I inspect the Widget tree inside Flutter Inspector I see that the renderObject has a size with the height of 19.
  Also, for a fontSize = 14 the value for the renderObject height size is 16.</p>
  
  <p>How is this 19(for fontSize 16) or 16(for fontSize 14) value calculated?</p>
  
  <p>I see that the browsers(Chrome at least) do a similar thing and I noticed that <code>line-height</code> CSS property does this, having a value around 1.166667. </p>
  
  <p>Going back to Flutter I noticed that the actual rendereBox height value is <code>fontSize*lineHeight</code> rounded (which is around 1.166667 too). </p>
  
  <p>I tried setting the <code>height</code> of the <code>TextStyle</code> to 1(<a href="https://api.flutter.dev/flutter/painting/TextStyle-class.html" rel="nofollow noreferrer">which seems it is the same</a> as the CSS property) but with no luck. The <code>TextStyle</code> <code>height</code> property has a default value of 1 already, not 1.166667.</p>
  
  <p>Where can I get the exact value of this lineHeight? How is ti calculated if it is not hardcoded somewhere?</p>