How to Choose the Right Duvet Tog for Winter

What a Tog Rating Actually Measures

Tog is simply a measure of thermal resistance — how well a duvet traps the warmth your body gives off. The higher the number, the warmer it sleeps. It says nothing about quality, loft or filling type, which is why a well-made 10.5 tog duvet can feel far more luxurious than a cheap 15 tog one. Think of tog as a thermostat, not a badge of luxury.

Most British bedding falls between 1 and 15 tog. Summer duvets sit at 1 to 4.5 tog, spring and autumn generally work at 7 to 10.5 tog, and true winter weights run from 12 to 15 tog. Before you buy anything heavier, though, it is worth checking what your bedroom actually does overnight — because the biggest mistake people make is buying for the weather outside rather than the temperature inside.

Match the Tog to Your Bedroom, Not the Forecast

A cold snap in January means very little if your bedroom sits at 20°C thanks to central heating and a well-insulated flat. Equally, a Georgian terrace with original sash windows can hover around 14°C even with the radiator on. Use the guide below as your starting point, then adjust based on how you actually sleep.

• 21°C and above: 4.5 tog. A heavy duvet here will have you throwing it off by 2am.
• 18°C to 21°C: 9 to 10.5 tog. This is the sweet spot for most heated British bedrooms.
• 16°C to 18°C: 12 to 13.5 tog. A proper winter weight, ideal for cooler houses and older properties.
• Below 16°C: 15 tog, or a layered duvet, plus a mattress topper to stop the cold rising from below.

If you wake up clammy in the middle of the night, your tog is too high. If you are pulling the duvet around your shoulders at 4am with cold feet, it is too low — or you are losing heat through draughts and a cold mattress.

Layering Beats One Heavy Duvet

An all-season duvet set is one of the most practical purchases you can make for a British climate. It usually pairs a 4.5 tog and a 9 tog duvet that clip together to make 13.5 tog. You get a light summer duvet, a mid-weight spring and autumn option, and a full winter weight, all from one buy — and you can adjust it the week the heating goes on or off.

If you share a bed with someone who sleeps at a different temperature, consider two single duvets on a king-size bed rather than one double. It sounds unconventional but it solves the nightly tug-of-war entirely. A folded throw or wool blanket over the foot of the bed is another simple way to add warmth exactly where you need it, without committing the whole night to a heavier tog.

The Filling Matters as Much as the Number

Two duvets with the same tog can feel completely different, because the filling decides how well moisture and heat move away from your body.

• Down and feather: warm for very little weight and highly breathable. Needs a daily shake to keep its loft, and a good cotton casing to stop feathers escaping.
• Wool: excellent at regulating temperature, so it suits people who overheat easily. Slightly heavier and usually needs gentle, specialist cleaning.
• Silk: light, naturally temperature-regulating and a good choice for hot sleepers, though it comes at a price.
• Microfibre and polyester: affordable, machine washable and great for allergy sufferers, but less breathable — which is why a synthetic 13.5 tog can feel stifling where a wool one does not.

The casing counts too. A tightly woven, down-proof cotton cover keeps fillings in place and lets air circulate, so it is worth paying a little more for it.

Small Adjustments That Change Everything

Bedding underneath you matters as much as the duvet on top. A cold mattress pulls heat out of your body all night, so a mattress topper adds insulation and softness in one go. Choose bedding to suit the season: brushed cotton or flannel sheets feel wonderfully cosy in winter, whilst pure cotton percale or linen keeps things breathable if you tend to overheat.

Other quick wins include wearing socks to bed if your feet are always cold, keeping the bedroom door closed to hold warmth, and using a hot water bottle to take the chill off the sheets rather than turning the heating up. If your duvet is warm but your feet are cold, the problem is usually draughts or a cold floor, not the tog.

Washing, Airing and Storing Your Winter Duvet

Air your duvet for twenty minutes each morning before making the bed — it lets trapped moisture escape and keeps the filling lofted. Shake it out weekly to redistribute the filling, particularly with down and feather.

Follow the care label closely. Most microfibre duvets wash happily at 40°C on a gentle cycle with a non-biological detergent. Down duvets can be washed, but they need a low-heat tumble dry with a couple of clean tennis balls to break up clumps — and they must be completely dry before use. Wool and silk are usually best dry cleaned.

When spring arrives, store your winter duvet in a breathable cotton bag rather than a plastic one, which traps damp and encourages mildew. Airing it thoroughly on a dry day before storing will see it come out fresh and lofty when the cold returns.