Side view of a bed with a duvet. The duvet gets thicker as the tog rises, and a thermometer on the left shows the room temperature.
Bedroom at night:
16 °C
Duvet
4.5 tog
7.5 tog
10.5 tog
13.5 tog
I usually sleep
warm (I kick the covers off)
about average
cold (cold feet, extra socks)
Chilly
Cool
Right
Warm
Hot
A rule-of-thumb model built from common retailer tog guides. Real comfort also depends on your pyjamas, mattress, partner and how well your home holds heat.