What size duvet do I need?

You will probably want some extra fabric to hang down on either side of the bed. If the duvet is the same size as the bed’s surface, it will waft off when you turn over or wiggle and may not even cover the bed’s surface with you under it, unless you are a string bean.

I don’t know what your units of measurement are (probably not inches).

Here’s a photo of a duvet with a very generous overhang. You may not want that much.

You have a little problem in that beds are not measured like that.

Beds come in single, double, king size and queen size, so you would want one that is the same name. You do want it to hang a little bit, but that will already be taken in to consideration by the maker.

140×200 sounds like a double to me.

A standard double bed in the US is 54” x 76.”

A standard double bed in europe is 140 X 200 yes (very much the same dimensions as given above for USA, 140 X 200 cm’s = 55.19 X 78.74, where would i be without google converter?)

My own is a standard double bed and the standard double duvet already takes a very slight overlap into account, unless you are sharing the bed with someone that is overweight, loves hogging the covers, and have acres of free space in your bedroom, there should be no need to get a larger size duvet.

As you have mentioned never using a duvet before, another thing you will need to consider is tog (unit of thermal resistance) it is advisable to consider seperate duvets for winter and summer in the Netherlands

This page contains recommendations from a British retailer which should be a close enough climate.
http://en.wikipedia.org/wiki/Tog_(unit)

It’s been my experience that extra duvet is more welcome than not. All things being equal, I’d say go for the largest duvet that seems reasonable.

Get the larger size for more warmth. It will have more room for you to turn over without dislodging the duvet.

Thanks for the help everyone! Went for the larger size.