How to take measurements?

[LalyRawr]

I've taken my measurements tonight and according to the size chart I'm using for the dress I'm getting my bust is a size 14, my waist a size 18 and my hips a size 10. Clearly I have gone horribly wrong somewhere as I promise I am proportional!

I used my OH's work tape as I don't have dressmakers measuring tape and it was in cm which I converted into inches online.

My bust is 40", my waist is 35" and my hips are 39".

Does that sound reasonable? Or have I measured wrong?

Also, if it helps (and if I get the link to work!) this is the size chart I'm using:

i42.photobucket.com/albums/e341/alyslyth/image-1_zpse8231af2.jpg

[JeffFaFa]

Id use another chart, choose a store you would usually shop at, my hips are 36 and im a size 10. It can completely depend where you shop though.