The measure of how effectively a duvet insulates heat: TOG

Consumers are increasingly getting pickier when it comes to the technical aspects of products. Similar to the functioning of a corporate purchasing department, individuals collect and consider various pieces of information to enable their decision making. A frequently referred parameter in the duvet segment, TOG is essentially a measure of how effectively a duvet insulates heat.

The abbreviation stands for “Thermal Overall Value” and is widely known and used around the globe. Here is a rundown of some key concepts about the TOG.

What does TOG mean?

TOG rating describes the warmth of “Thermal Resistance” of a product and is widely used for products like duvets and outerwear. It accordingly refers to a scale of thermal resistance, as in how well the product traps heat released from the body.

The Shirley Institute in Manchester, England developed the TOG as an easy-to-follow alternative to the SI unit.

The basic unit of insulation coefficient is the RSI, (1 m2K/W) whereas 1 tog = 0.1 RSI.

In other words, the thermal resistance in TOGs is equal to ten times the temperature difference (in °C) between the two surfaces of a material, when the flow of heat is equal to one watt per square metre.[1]

TOG value refers to how effective a duvet is in trapping body heat.

TOG – Emergence and Meaning

A quintessentially English term, the name comes from the informal word togs for ‘clothing’, which itself was probably derived from the word toga, a Roman garment. The backronym “thermal overall grade” is also attested.

Why does TOG matter?

TOG is important as it indicates the warmth a duvet can provide.

Referring to the duvet`s capacity in trapping body heat, ie its insulative power, which TOG is right for you will depend on two key factors: the temperature in your bedroom and your own preferences.

A TOG rating is affected by the type of fibre or filling, depending on the desired level of warmth.

TOG values by Country, Season and Temperature

Maya’s Professional’s Recommended TOG levels for Turkey

6,5 TOG (coolest)

13,5 TOG (warmest)

If you need a light and airy duvet ideal for summer, 6,5 TOG would be right for you.

10,5 TOG and above are appropriate for winter temperatures.

If you need an all-rounder for winter and summer alike, try a 10,5 TOG duvet.

There are various choices for different personal preferences and seasonal temperatures.

TOG ratings and warmth / Turkey

6,6 TOG – Cool

7,5 TOG – Warm

8,5 TOG – Medium Warm

10,5 TOG – Hot

13,5 TOG – Very Hot

TOG ratings and Seasons / Turkey

4 – 6 TOG – Summer

6 – 11 TOG – Spring and Autumn

11 and above – Winter

TOG ratings and Seasons / England

4,5 TOG – Summer

9,0 – 10,5 TOG – Spring and Autumn

12,0 – 13,5 – Winter

In Germany, all-seasons duvets with 7.4 TOG are very popular and can be used all year around.

TOG for goose down duvets

Down used for duvets refers to the soft and fluffy layer of 3-dimensional structure that is closest to a goose’s skin and is primarily located in the neck area and on back of the bird. The latter as a layer is highly flexible which helps in preserving the form of the garment whereas neck layers provide fluffiness, density, and warmth.

Does TOG affect duvet weight?

The weight of the duvet does not relate to its TOG rating. Duvets filled with feathers or down naturally have better thermal properties than synthetic versions. This means you don’t need as much filling to achieve the same rating, often making them lighter.

Personal preferences and sleep habits will indicate what sort of filling material to opt for as well as the TOG rating to choose from. The right combination of TOG rating and filling material will ensure a comfortable night’s sleep.