Hi Spud & Chloë Friends,
I noticed on Ravelry that a few people who knit up the Heart Tape Measure have said that it turned out bigger than they expected. I thought maybe it would help visualize it if I held up my version with a ruler. The finished Heart Tape Measure is about 3-inches wide not including the edging. It is about 3 1/2-inches including the edging slightly stretched.
The same measurements apply to the length.
I hope that helps a little. It is really important to get the correct gauge when knitting cozies because they need to fit. My gauge measures at 5.5 stitches per inch. If you find that your heart is a little big you could try going down a needle size.