# How to make equation text size to be normal

The letters in my equation are shrinking and I'm trying to revert that:

I'd like them to appear as follows:

If you notice you can see that the parenthesis' size on second image vary like 3 times while on the first equation it doesn't change much. In the first image the fraction W over h are shrinking down how do I make them not to shrink?

$$\Delta L = 0.412 \cdot h \frac{(\epsilon_{ref} + 0.3)\left( \frac{W}{h} + 0.264 \right)} {(\epsilon_{ref} - 0.258)\left( \frac{W}{h} + 0.8 \right)} \label{for:fringes}$$


I'd like to know how to change the equation's font to mach the on in the second image.

Thank you very much.

Use the following command,

$$\dfrac{\Delta L}{h} = 0.412 \dfrac{(\epsilon_{ref} + 0.3)\left( \dfrac{W}{h} + 0.264 \right)} {(\epsilon_{ref} - 0.258)\left( \dfrac{W}{h} + 0.8 \right)} \label{for:fringes}$$


Use package amsmath (mathtools), \dfrac and \text:

\documentclass[12pt]{article}
\usepackage{mathtools}
\begin{document}

$$\Delta L = 0.412 \cdot h \dfrac{(\epsilon_\text{ref} + 0.3) \left( \dfrac{W}{h} + 0.264 \right)} {(\epsilon_\text{ref} - 0.258) \left( \dfrac{W}{h} + 0.8 \right)}\label{for:fringes}$$

\end{document}


• although not strictly necessary, it would probably be a good idea to put braces around the entire {\text{ref}} subscript. – barbara beeton Jul 1 '15 at 12:42