--- title: "How to Choose a Duvet" description: "Simple UK guide to choosing duvet TOG, fill and size — no brand rankings or sales talk." url: "https://bedguide.co.uk/bedding/how-to-choose-a-duvet/" category: "bedding" primary_entity: "how to choose a duvet" date_published: 2026-08-03 date_modified: 2026-08-28 --- # How to Choose a Duvet > Choose a duvet by TOG for warmth, fill type for loft and care, and size to match the mattress plan. UK households often use about 4.5 TOG for summer, 10.5 TOG mid-range and 13.5+ TOG for cold rooms. Down uses fill power; synthetics use fibre shape. Allergies and wash routines often decide natural versus hollowfibre more than warmth alone. Materials covered: down and feather, hollowfibre, microfibre, wool fillings. Key facts: - Common UK TOG bands: 4.5 / 10.5 / 13.5 — Summer, mid-range and cold-room starting points. Not medical advice. - Two different scores: TOG ≠ fill power — TOG is warmth. Fill power is down loft efficiency. - Duvet size: Match the plan — A UK King mattress is 150 × 200 cm. Read the pack centimetres. - How to choose: Room first — A cold spare room and a warm flat need different TOG. ## What three choices decide a duvet? Choose warmth first, then fill, then size. Warmth is [TOG](/glossary/tog-rating) — a lab measure of how well the finished duvet holds heat. Fill is down, feather mix, hollowfibre, microfibre or wool. Size must match the mattress in centimetres, not only a name. A “King” duvet for the wrong market will not drape a UK King (150 × 200 cm) the same way. Do not start with a brand. Start with the room. A cold spare room and a warm flat need different TOG even if the mattress is the same. ## What TOG should I pick? TOG measures insulation of the finished duvet, not how fluffy it looks in a bag. Full science: [duvets fill and TOG](/bedding/duvets-fill-and-tog). UK shops often talk in bands. They are starting points, not medical advice and not a promise you will sleep at one temperature. | TOG (approx.) | Often used for | | --- | --- | | ~4.5 | Warm rooms / summer | | ~9–10.5 | Many year-round homes | | ~13.5+ | Cold rooms / winter | Hot sleepers should look at the room and the duvet together. See [hot sleeper setup](/environment/hot-sleeper-bedroom-setup). A winter TOG year-round can make you blame the mattress for heat. That is a duvet problem first. All-seasons packs stitch or layer two TOGs. You still read each layer’s TOG. Adding 4.5 and 9.0 is not magic. It is two layers with air between them. ## How do I choose fill type? Down and feather loft well. [Fill power](/glossary/fill-power) describes how much space a given mass of down occupies. It is not TOG. A high-fill-power, low-TOG duvet can sleep light and still look plump. Hollowfibre and other synthetics are often easier to wash at home. Wool buffers moisture for some people. Check the wash label before you buy, not after a spill. | Fill | Strength | Watch for | | --- | --- | --- | | Down / feather | Loft; fill power | Care labels; some allergy preferences | | Hollowfibre / synthetic | Often easier home wash | May loft differently over years | | Wool | Moisture buffering for some people | Check wash rules | Compare: [down vs hollowfibre](/compare/down-vs-hollowfibre) and [wool vs synthetic](/compare/wool-vs-synthetic-duvet). Allergy and laundry often decide this step more than warmth. If you need frequent hot washes, pick a fill the label allows. See [washing bedding](/bedding/washing-bedding-and-pillows). ## What size duvet matches a UK mattress? Use [UK mattress sizes](/sizing/uk-standard-bed-sizes) in centimetres. A UK Double mattress is 135 × 190 cm. A UK King is 150 × 200 cm. A UK Super King is 180 × 200 cm. The duvet should be labelled for that market, or you should read the duvet’s own width and length. EU and UK names collide. A duvet bought as “King” abroad may be cut for 160 × 200 cm. That is not a UK King. Measure both. Overhang is personal. Too little overhang lets the edges fall off. Too much pools on the floor and feels heavier. ## What mistakes should I avoid? - Using winter TOG all year, then blaming the mattress for heat. - Mixing EU duvet sizes with UK mattress names. - Buying a [weighted blanket](/bedding/weighted-blankets) and expecting TOG warmth. Weighted blankets are pressure tools. They are not a TOG rating. - Skipping the wash label when someone in the home has allergies. See the [allergy-aware path](/learn/allergy-aware-sleep). - Pairing a huge Super King duvet with a small frame so it drags and sheds heat oddly. [Electric blankets](/bedding/electric-blankets) add heat on top of TOG. Read both instructions. Do not stack heat sources you do not understand. ## Related BedGuide entries - [Duvets, fill and TOG](/bedding/duvets-fill-and-tog) - [Electric blankets](/bedding/electric-blankets) - [Bed sheets](/bedding/bed-sheets-materials) - [UK fitted sheet sizes](/sizing/uk-fitted-sheet-sizes) ## Frequently asked questions ### What TOG duvet do I need? Rough UK framing: ~4.5 TOG for warm rooms or summer, ~10.5 TOG for many year-round uses, ~13.5+ TOG for cold rooms or winter. Personal preference and heating matter more than a single fixed number. ### What size duvet for a UK King mattress? Buy a duvet labelled for UK King, or confirm the duvet's width and length cover the 150 × 200 cm mattress with your preferred overhang. Names must match the mattress market you are buying for. ### Is a higher fill power always warmer? Fill power describes loft efficiency of down, not TOG by itself. A low-TOG high-fill-power duvet can still sleep light. Read TOG for warmth and fill power for loft quality. ### Should couples buy two single duvets? Some couples use two singles on a zip-and-link or King bed so each person keeps their own TOG. That is a setup choice, not a rule. Size names must still match the mattress centimetres. --- Source: https://bedguide.co.uk/bedding/how-to-choose-a-duvet/ · BedGuide — educational encyclopedia, no affiliate commission. Facts checked against official sources where possible; see https://bedguide.co.uk/editorial-policy. Report an error: https://bedguide.co.uk/corrections.