# How to fix overfull in inline math?

How do I fix this overfull warning that is caused by the inline math equation? When I used \sloppy on the paragraph related, underfull warning appeared instead. I've included a MWE below. If it helps, I use lualatex.

\documentclass{report}

\begin{document}
Firstly, the processing time in the Client-side Mobile Application is calculated by
substracting the end time with the start time, such as $ProcessingTime = EndTime - StartTime$
using the help of an API in React Native.
\end{document}

• Not sure if it will help with the overfull warning but you should probably do $$\mathit{ProcessingTime} = \mathit{EndTime} - \mathit{StartTime}$$ for better kerning. Sep 19 at 15:44
• I don't get any warnings with or without \sloppy. How old is you version? Sep 19 at 20:03
• @JohnKormylo I'm using Version 4.70b latexmk with -pdflua flag. Sep 20 at 0:32

Here are some possibilities:

• Live with over- and underful boxes as long as they are not too bad.

• Rephrase the sentence to allow for better line breaks.

• Replace inline math by displayed math.

Unrelated: as noted by @Willoughby in the comments, it is better to use \mathit for words in math mode that signify variables.

\documentclass{report}

\begin{document}

Firstly, the processing time in the Client-side Mobile Application is calculated by substracting the start from the end
time, $\mathit{ProcessingTime} = \mathit{EndTime} - \mathit{StartTime}$, using the help of an API in React
Native.

Firstly, the processing time in the Client-side Mobile Application is calculated by substracting the start from the end
time
$\mathit{ProcessingTime} = \mathit{EndTime} - \mathit{StartTime}$
using the help of an API in React Native.

\end{document}