Here is our size guide to help you:

Mattress         Duvet
60 x 120 -->   75 x 120
70 x 140 -->   100 x 140
90 x 190 -->   140 x 200
140 x 190 -->  220 x 240
140 x 200 -->  220 x 240
160 x 200 -->  240 x 260