A guide to tog ratings

4.5 tog

for summer use

9.0 tog for spring/autumn, particularly in milder parts of the country
10.5 tog for spring/autumn for those with central heating, who share a bed (more heat is generated)
12.0 tog for slightly more warmth
13.5 tog for colder seasons, or for those who prefer a warm duvet
13.5 tog
Four Seasons
3 warmth options from 2 duvets. A 4.5 tog for summer, 9.0 tog for spring/autumn, and join them together to make a 13.5 tog for winter