How much Fabric needed for a tie blanket?

I'm making my sister a tie/no sew blanket for christmas and I was wondering how much fabric i'll need to make it. Also if you know about how much it would cost. Thanks:)
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tie

if you're not sure, go with the 2 1/2, its always better to have more than less. and for a fleece tie blanket, you need double the area of the blanket and then extra for the ties, so it really depends on the size.

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