How much bigger then the quilt does the cover have to be?

[LowLevelWhinging]

A friend has asked me to make a quilt cover for her toddler's cotbed. (very trusting of her!)

It's just a rectangle right?

But how much bigger should I make it so that it's not too snug? add an inch to the size of the quilt (so half an inch either side plus hem allowances)?

And then extra for the bit with buttons/buttonholes on.

Any tips or things I haven't thought of?

TIA

It's a guessing thing, but I think your guess is about right. Could go a little bit smaller, just like just one cm, but it will pucker a bit.

Surely it depends how plump the quilt is ?

Not helping am I!!! Could u sneak into mother care and measure one ?

I dunno, duvet covers are the same size whether it's a 3.5 or 12.5 tog duvet, no?

I am selling cot duvet covers that measure 97 x 114 cm, but no idea if that's standard.

OK thanks. And good idea about measuring one. I'll get other mate to measure one that she has!