What tog duvet do you actually need? A UK guide by season
Tog is the one bedding number nearly everyone gets wrong. It is not a measure of quality, thickness or how expensive a duvet is. It is a measure of thermal resistance — how well the duvet stops your body heat escaping. A 13.5 tog duvet is not a better duvet than a 4.5 tog one. It is a warmer one, and in a centrally heated flat in September that makes it the worse choice.
The ratings, in plain terms
- 1–4.5 tog — summer. Right for June to August in most of the UK, and right all year in a bedroom that runs warm or sits above a heated room.
- 7–10.5 tog — spring and autumn. This is the rating most British homes could use for about eight months of the year, and the one people under-buy.
- 12–13.5 tog — winter. Genuinely cold bedrooms, draughty older houses, or anyone who turns the heating off overnight.
- 15 tog and above — rare, and usually too much. If you are waking up damp, the tog is too high, not the room too cold.
The all-seasons trick
An all-seasons duvet is two duvets — typically a 4.5 tog and a 9 tog — with poppers or ties along the edges. Use the 4.5 alone in summer, the 9 alone in spring and autumn, and clip them together for 13.5 tog in winter. It costs a little more than a single winter duvet and replaces three. If you are buying from scratch, this is almost always the right answer. Browse duvets and sets and duvets and down comforters.
Filling matters as much as tog
Two duvets at the same tog can feel completely different.
- Down and feather — the best warmth-to-weight ratio. Light on the body, drapes around you, lasts for years if you shake it out. Costs more, needs specialist cleaning, and is not for anyone with a feather allergy.
- Microfibre — fine strands that mimic down. Soft, cheap, machine washable, and the sensible everyday choice. It will flatten sooner than down.
- Hollowfibre — hollow polyester strands. Bouncier and heavier-feeling than microfibre, very durable, very washable. A good choice for children's beds.
- Wool and bamboo — heavier, and better at moving moisture than at trapping heat. Worth considering if you overheat and wake up clammy rather than cold.
Sizing: buy up, not exact
UK duvet sizes are generous but the classic mistake is matching the duvet to the mattress. A double duvet (200 × 200 cm) on a double bed leaves almost nothing to tuck under two people who both pull. If two of you share and one of you is a duvet thief, buy a king duvet for a double bed. It is the cheapest marriage guidance available.
Do not forget what is under and over it
Warmth comes in layers, and the duvet is only one. A mattress topper stops heat draining downwards into a cold mattress, which is why the same duvet feels warmer on a topped bed. A bed blanket across the foot lets you add or remove warmth without changing duvets. And a duvet cover in brushed cotton or flannel adds a genuine tog or so over a percale one.
Care, briefly
Air the duvet rather than washing it — most need washing only once or twice a year, and a hot wash is what destroys them. Shake it out daily so the filling redistributes; a duvet that has all migrated to one end is not worn out, it is just lumpy. Store the off-season one in a breathable cotton bag rather than sealed plastic, which traps moisture.
Ready to look? Start with duvets, comforters and sets and sheets and pillowcases. Our bedding care guide covers washing and layering in more depth.
