The term tog is a measure of how effectively a duvet insulates heat. The higher the tog rating, the warmer the duvet will be. Tog ratings range from 2.5 which is very cool and super lightweight to 15 which is the warmest and generally the heaviest. The thinnest, lightest duvet available is typically a 4.5 tog, while the thickest and heaviest is usually around a 13.5 tog. It's important to note that the tog rating refers to a duvet's overall effectiveness at trapping heat, rather than its weight or thickness.

The right tog rating for you will depend on your personal preferences and environmental factors, such as the temperature of your bedroom and the season. For summer and spring, a lightweight duvet with a tog rating of 4.5 is recommended to keep you cool without overheating. Some people may prefer a slightly heavier duvet, such as a 7.5 tog, even in warmer weather. Duvets made from synthetic fibres are usually more breathable during this time of year. During winter and autumn, it's best to switch to a duvet with a higher tog rating for extra insulation on chilly nights. A 13.5 tog winter duvet is suitable for colder months, but you can adjust the tog rating based on the temperature in your bedroom. Ideally, you should aim to keep your bedroom heated to between 18 and 21 degrees Celsius overnight. If your home gets colder, you can consider using a duvet with a higher tog rating, up to 15 tog.

Summer Weight Duvets

Personal preference also plays a role in choosing the right duvet tog. Some people may prefer the snug feeling of a thicker duvet, while others may find it too heavy. If you're unsure, a duvet with a medium-warm tog rating of around 10.5 tog is a good option. You can also add a quilt or throw for extra warmth on colder nights. This is especially useful if you share a bed with a partner who has different duvet preferences, as you can adjust the weight and thickness on your side of the bed without disturbing them. The type of mattress you sleep on can also affect how warm you feel in bed. Memory foam mattresses tend to retain more heat compared to traditional pocket sprung styles. If you have a memory foam mattress and find it quite warm to sleep on, using a light summer duvet all year round and switching to a slightly thicker 13.5 tog duvet in winter can help prevent overheating.


For children, it is recommended to use a lightweight duvet cover from around one year old, preferably with no more than 4 togs. If you're concerned about them getting too cold, monitor the temperature of their bedroom and add blankets as needed. Once they reach three years old, you can consider increasing the tog rating, especially during winter. Babies under 12 months old should not have any kind of duvet, as it poses a suffocation risk. Infants of this age can easily overheat, so it's safer and more comfortable for them to use lightweight baby blankets and sleeping bags instead. You can check if your baby is comfortable by feeling their tummy with the back of your hand to see if they're too hot, and adjust their blankets accordingly.

Coolmax Cooling Duvets