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.

bedding

How to Choose a Duvet

Entity: how to choose a duvet

Layered duvet and pillows on a king bed with a tall fabric headboard — Sheets, duvet and pillows work together with the bed — not just the mattress alone.

In short

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.

Educational decision diagram for duvet TOG bands, fill type and mattress size matching — Pick TOG for room climate, fill for care and loft, size for mattress centimetres.

Three decisions (in order)

1. Warmth — TOG

TOG measures insulation of the finished duvet. Full science: duvets fill and TOG.

Rough UK bands:

TOG (approx.)	Often used for
~4.5	Warm rooms / summer
~9–10.5	Many year-round homes
~13.5+	Cold rooms / winter

Hot sleepers: start with room and TOG — see hot sleeper setup.

2. Fill — care and loft

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 and wool vs synthetic.

3. Size — match the mattress

Use UK mattress sizes in centimetres. A “King” duvet for the wrong market will not drape the same.

Allergy and laundry

If you need frequent hot washes, choose fills and covers the label allows — see washing bedding and the allergy-aware path.

Common mistakes

Using winter TOG year-round, then blaming the mattress for heat
Mixing EU duvet sizes with UK mattress names
Buying weighted blankets expecting TOG warmth (weighted blankets are pressure tools)

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.