finding out the size of the letters - and the type

[Ofnuts]

1. Go to WhatFontIs or similar site to identify a similar font if you don' t know already, and install if you haven't got it already
   
2. Create a text later over your text using the same font and text and adjust the size until they match.
   

Here "Roboto Bold 48" matches the height but is too wide, while "Roboto Bold 47" matches the width but is a tad small (and this also shows some small shape discrepancies, so "Roboto Bold" is likely not the exact font (which is expected because it's is mostly designed for smartphone screens).

   

   

It is also possible that the text was produced with slight font alterations (for instance using a -0.5 spacing at size 48 gives a better match) or even that the text was scaled horizontally.