The Tog Rating of Your Duvet

The same tree pictured in summer, spring, autumn and winter

Thermal Overall Grade

The tog rating of a duvet is a measurement that indicates its heat retention capacity. It stands for “thermal overall grade.” Essentially, the higher the tog rating, the warmer the duvet will keep you at night.

The insulating power of a duvet is determined by several factors, including the amount of down, its quality, and the way in which the duvet is manufactured. Using the tog rating, we can sort duvets into seasonal variants based on the amount of warmth they provide. Continue reading to see how this helps you find the right duvet and to learn about the science behind tog testing.

At, all of our duvets have a verified tog rating that lets you know how warm they are. No one wants to sweat or shiver through the night, so getting a duvet with just the right amount of warmth is essential. Luckily, the tog rating system is scientific and precise, making it easy to choose the right duvet.

Tog Rating, From Lab to Bedroom

The tog rating of a duvet is determined using a precise testing method. It involves applying heat to one side of the fabric and measuring the heat flow to the other side. For a down duvet, the tog value is calculated by multiplying the temperature difference between the two sides (in degrees Celsius) by ten when the heat flow across the fabric is equal to one watt per square meter.

To assess the tog ratings of duvets, meticulous measurements are taken. The duvet is carefully spread over a large rectangular hotplate in a room with a controlled ambient temperature of 19.5-20.5 °C. The hotplate is set to a specific temperature range of 32.5-33.5 °C. Multiple points on the duvet are then measured to determine the average thermal resistance of the material.

4.5 Tog: The Summer Duvet

Our summer duvets are light and airy, almost unbelievably so. Sewn through fabric and high quality down ensures these duvets will keep you cool while providing a comfortable, breathable covering throughout the summer. With a tog rating of 4.5, they are suitable for most bedrooms.

The summer duvets manufactured by Dickenbergh, Falkenreck, Dickenbergh Manufaktur and Kauffmann 1st Class are particularly light and cool. Those from Kauffmann, Otto Keller and Bielefelder Verse are slightly warmer because of differing manufacturing techniques.

Explore our full range of Summer duvets

6.0 Tog: The SummerPlus Duvet

SummerPlus duvets are also sewn through and light, though less so than summer duvets. This means they are suitable for a greater part of the year, possibly from spring through to mid-autumn, depending on your local climate. If your home is well-heated, then a SummerPlus duvet can be used year-round.

The SummerPlus duvets from Otto Keller and Dickenbergh tend to be a little bit cooler. Those from Kauffmann and Falkenreck are warmer.

Explore our full range of SummerPlus duvets

9.0 Tog: The Spring/Autumn Duvet

For many people, a Spring/Autumn duvet is ideal because it can be used comfortably almost the entire year in most homes. Spring/Autumn duvets have a tog rating of 9.0. Some are sewn through, others are of a baffle box construction. These duvets will not only keep you warm during the cooler nights, but are also light enough to not necessitate a change every time there is a hot spell.

The coolest Spring/Autumn duvets are those from Otto Keller, Bielefelder Verse and Kauffmann 1st Class. Dickenbergh, Falkenreck and Dickenbergh Manufaktur duvets are a bit warmer. The warmest Spring/Autumn duvets are made by Kauffmann.

Explore our full range of Spring/Autumn duvets

12.0 Tog: The Winter Duvet

Satisfyingly warm, decadently thick and luxuriously soft, winter duvets are perfect for those who need to wrap themselves up in the winter, whether that be for comfort or to fight off the chills. With a tog rating of 12.0, winter duvets will keep you warm and cozy in regular winter conditions. They are manufactured using the baffle box technique to provide optimal insulation.

As with other classes, the winter duvets from Dickenbergh and Kauffmann 1st Class are slightly less warm. The warmest winter duvets are made by Kauffmann, Otto Keller, Falkenreck, Bielefelder Verse and Dickenbergh Manufaktur.

Explore our full range of Winter duvets

15.0 Tog: The WinterPlus Duvet

The warmest of the warm, WinterPlus duvets offer unparalleled warmth and comfort. A tog value of 15.0 means WinterPlus duvets can bring luxurious and comfortable sleep in the most extreme climates. Their insulating power is so great that we generally do not recommend their use in houses with effective central heating, except for those individuals who require extreme amounts of insulation.

The lightest WinterPlus duvets are those from Dickenbergh and Kauffmann 1st Class. Warmer and heavier WinterPlus duvets are made by Kauffmann, Otto Keller, Falkenreck, Bielefelder Verse and Dickenbergh Manufaktur.

Explore our full range of WinterPlus duvets

The All Seasons Duvet

An exotic species, these are truly duvets for all seasons. Called the duo-duvet in Germany, All Seasons duvets consist of two duvets with different tog ratings that can be used separately or in tandem.

The lighter of the two duvets is perfect for keeping you cool, fresh, and dry on hot summer nights. When things start to cool down come autumn, you can switch to the warmer duvet. Once winter arrives, the two are easily combined to create a seamless winter duvet.

Explore our full range of All Seasons duvets

Is a Higher Tog Rating Better?

Tog rating doesn’t measure the quality of a duvet or how comfortable the fabric feels against your skin. It does not reflect the weight of the duvet either. Tog tells us how efficiently a product will trap warmth. This is known as thermal resistance. The higher the tog rating, the warmer the duvet will feel. However, it’s important to note that tog ratings are measured under laboratory conditions.

Another factor that can affect how warm a duvet actually feels is the overall quality of its manufacturing. A poorly constructed duvet made from cheap materials might have a certain tog rating when brand new and measured in a laboratory, but after a few uses this low-quality duvet may lose some of its insulating capacity. The duvets available on this website all come from reliable manufacturers and should remain close to their tested tog rating for many years.

Down Duvet Buying Guide

Choose Your Duvet in 4 Simple Steps.

  1. Duvet size: Which size do I need?
  2. Tog: Pick the right tog rating
  3. Fill power: Understanding Fill Power
  4. Duvet Fabric: Quality fabric for comfort

Compare all down duvets by duvet price, size, season, brand, fill power, fabric and down.

Do you have any questions? Let us know!
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