Ikea duvet covers- do they fit other duvets apart from ones at Ikea?

[Icantcook]

..or do I need to buy an ikea duvet for them to fit right?

I don't know for sure, but I would expect not. I'm pretty sure Ikea beds are non-standard UK sizes, so I think it would follow that bed linen would be non-standard too. Hopefully someone else will actually Know (rather than guessing)

I have an ikea duvet cover on a tesco duvet. Fits fine.

They've changed them and they now have standard british sizes too. Bought one a couple of weeks ago for a single bed, fits perfectly!

Great news! Thanks all!