# rounded box around text

 \newcommand*\round[2]{%
\tikz[baseline=(char.base)]
\node[anchor=north west, draw,rectangle ,rounded corners, inner xsep=5.6cm,
minimum size=5.5mm, height=3.6mm, fill=#2,#2,text=white,align= left](char){#1};
%
}



I am getting this, but I need the text to be left aligned and the round boxes to be the same size.

• Welcome to TeX-SE! Are you aware of the tcolorbox package? – user121799 May 27 at 1:54

I have changed some of your parameters and condensed them to what you need. Keep in mind that text width is what you needed (you don't have to use align = left because it is set to left by default).

\documentclass{article}
\usepackage{tikz}
\newcommand\round[2]{\par
\noindent\begin{tikzpicture}%
\node[draw = #1, fill = #1, rectangle, rounded corners,
minimum size = 5.5mm, text = white, text width = 10cm](char){#2};
\end{tikzpicture}\par%
}%
\begin{document}
\round{blue}{First Title}
some text\\
\round{red}{Second Title}
some text\\
\end{document}


\documentclass{article}
\usepackage{tikz}
\newcommand*\round[2][blue]{%
\tikz[baseline=(char.base)]\node[shape=rectangle,
rounded corners, minimum width=\textwidth,text width=\textwidth-3em,
minimum  height=2em,text depth=0.3em,
fill=#1,text=white,align=left,font=\sffamily](char){#2};%
}
\begin{document}
\noindent
\round{Some text}

\noindent
\round[blue!70!black]{Some other text}

\end{document}


However, I feel you might be better off using tcolorbox, which is based on tikz. Using this answer you may do

\documentclass{article}
\usepackage[most]{tcolorbox}

\newtcolorbox{rounded}[1][]{enhanced jigsaw,colback=blue,
boxrule=0pt,arc=2mm,auto outer arc,boxsep=0pt,coltext={white},fontupper=\sffamily,
#1}

\begin{document}

\begin{rounded}
Some text
\end{rounded}

\begin{rounded}[colback=blue!70!black]
Some more text
\end{rounded}
\end{document}