As a starting point: a 250 g/m² duvet for spring and autumn, a 300 g/m² duvet for year-round use in a heated room and a 400 g/m² duvet for winter or for mountain properties. The duvet size is chosen by the width of the mattress, and the duvet cover by the size of the duvet. That is the short rule, and it is enough to get started.
The long rule is that the weight is not chosen for the hotel, but for each room. An inner room with constant heating and a corner room that cools down in the early hours may call for different duvets within the same building, and erring on the side of too much is usually worse than falling slightly short. This guide explains what the weight measures, why excess warmth is a problem, how to decide room by room and how to stop the different weights from complicating your storeroom.
What the weight measures, and what it does not
The weight states the grams of fibre per square metre of duvet. It is neither the total weight of the duvet nor a universal temperature scale. It is used to compare duvets of the same fibre and the same construction: between two hollow-fibre duvets quilted in the same way, the 400 g/m² one contains more fibre and is warmer than the 250. Between duvets of different fibres or constructions, the number by itself is not enough.
The reason is that warmth does not come from the duvet alone, but from the whole bed. Lin and Deng, of the Hong Kong Polytechnic University, used a thermal manikin to measure the total insulation of many common bedding combinations and obtained values between 0.90 and 4.89 clo depending on the bedding, the mattress, the sleepwear and the part of the body covered (Building and Environment, 2008). In other words, the same duvet provides different warmth on one mattress or another, with one set of nightwear or another, and with the guest more or less covered.
Laboratories that assess duvets do not stop at weight either: the Hohenstein institute measures insulation with a thermal manikin and breathability with a sweating one, because a duvet must insulate and, at the same time, keep the microclimate of the bed dry (Wölfling and Classen, 2020). The weight is the lever you control; the room decides how much it needs.
Why too much warmth is worse than too little
Intuition says that, when in doubt, the thicker duvet is better. Sleep research points the other way. In their 2012 review in the Journal of Physiological Anthropology, Okamoto-Mizuno and Mizuno explain that the microclimate under the covers stays at around 32–34 °C and 40–60 % relative humidity during normal sleep, and that, with bedding, heat exposure increases awakenings and reduces deep sleep and REM sleep. With the same bedding, moderate cold in the room affects sleep much less, provided the bed is warm enough.
Humidity makes the problem worse: according to the same review, if sweat does not evaporate, the skin stays wet and the heat load increases. A 400 g/m² duvet in a heated room does not give more comfort; it gives a guest who throws off the covers, a window opened at midnight or a complaint about the heat. That is why the weight should cover a normal night in that room, and extra warmth should be something the guest can add, not something they cannot take away.
The three weights, room by room
Our duvet is made of siliconised hollow fibre, quilted in a diamond pattern, in 250, 300 and 400 g/m². This table translates the guidance on its product sheet into specific situations in a property:
| Room situation | Starting weight | What to watch |
|---|---|---|
| Inner room, heated all night | 300 g/m² all year, or 250 g/m² if the heating is set high | Complaints about heat and open windows |
| With timed heating that switches off in the early hours | 300 g/m² | Early-morning temperature and requests for a blanket |
| Corner room, north-facing or with cold outside walls | 300 g/m² with a spare blanket, or 400 g/m² if it regularly gets cold | Difference from neighbouring rooms |
| Mountain, inland or without central heating in winter | 400 g/m² | That it is not also used in spring |
| Spring and autumn season in a mild climate | 250 g/m² | The first cold nights of autumn |
If just one room needs 400 g/m², there is no need to upgrade the whole building: a clean spare blanket in the wardrobe takes care of the guest who feels the cold without loading every bed.
A useful calculation: how much fibre goes into the washing machine
The weight also tells you how much the fibre in each duvet weighs. The calculation is area × weight. For our five sizes:
| Duvet size | Area | 250 g/m² | 300 g/m² | 400 g/m² |
|---|---|---|---|---|
| 150 × 220 cm | 3.30 m² | ≈ 0.8 kg | ≈ 1.0 kg | ≈ 1.3 kg |
| 180 × 220 cm | 3.96 m² | ≈ 1.0 kg | ≈ 1.2 kg | ≈ 1.6 kg |
| 220 × 220 cm | 4.84 m² | ≈ 1.2 kg | ≈ 1.5 kg | ≈ 1.9 kg |
| 240 × 220 cm | 5.28 m² | ≈ 1.3 kg | ≈ 1.6 kg | ≈ 2.1 kg |
| 260 × 220 cm | 5.72 m² | ≈ 1.4 kg | ≈ 1.7 kg | ≈ 2.3 kg |
This is an estimate of the fibre; the outer fabric adds a little more. It helps with two decisions: how many duvets fit in one load without exceeding the capacity of your washing machine, and how much space the winter set will take up when it is not on the beds.
Measure the room before choosing
The outdoor temperature of the town is no substitute for this check: the guest sleeps inside the room. Choose three representative rooms, the warmest, one in between and the coldest, and over several nights at normal occupancy record:
- The temperature next to the bed at bedtime and in the early hours, before the heating comes on.
- Whether the heating runs all night or is on a timer, and what time it switches off.
- Whether there are draughty windows, cold floors or outside walls.
- Whether an extra blanket is already offered, and how often it is used or requested.
With that information, the starting rule is 250 g/m² in mild rooms, 300 in the in-between ones and 400 only in those that really get cold. Record the result by room number, not by floor.
The size: the duvet by the bed, the cover by the duvet
Weight and size are two separate decisions. The weight tells you how much fibre there is in each square metre; the size, how much of the bed it covers. This is how our duvets match the width of the mattress:
| Bed width | Duvet size | Duvet cover |
|---|---|---|
| 90 cm | 150 × 220 cm | 150 × 220 cm |
| 105 cm | 180 × 220 cm | 180 × 220 cm |
| 135 cm | 220 × 220 cm | 220 × 220 cm |
| 150 cm | 240 × 220 cm | 240 × 220 cm |
| 160, 180 and 200 cm | 260 × 220 cm | 260 × 220 cm |
Note the 160 bed: it takes the 260 × 220 duvet, not the 240. Ten extra centimetres of mattress show on a duvet that no longer hangs evenly on both sides.
The duvet cover is ordered in the same size as the duvet, not the bed. If your property still has duvets from earlier purchases, measure the one you have, laid flat and without stretching it, or read its label: two manufacturers may assign different sizes to the same bed, and what counts is the centimetres. If you are still deciding between dressing the bed with a duvet or with a flat sheet and blanket, the comparison is in our guide duvet cover or flat sheet.
One, two or three weights: what it costs in the storeroom
Each weight you add is one more item per size. With five bed sizes and two weights, the storeroom goes from five duvet items to ten, and each one needs a separate reserve. It is the same effect we describe in the cost of not standardising: what multiplies is not what is on the beds, but what has to be kept just in case.
There are two reasonable strategies:
- A single weight all year round (usually 300 g/m²) and a spare blanket for cold nights. It is the simplest option for heated hotels and city apartments: one item per size and no seasonal change on the beds.
- Two alternating weights (250 in spring and autumn and 400 in winter). This makes sense for mountain or inland properties with cold winters, but it means washing, drying and storing a full set twice a year.
If you choose two weights, mark them. A label or a colour mark with the weight in the corner of the duvet prevents the 400 from ending up in a heated room; in how to mark bed linen we explain systems that withstand the laundry.
Test on a small scale before equipping everything
Before placing an order for every bed, put one unit of each candidate weight in the rooms you measured and record for one or two weeks:
| What to observe | How to record it |
|---|---|
| Guest comments about cold or heat | By room and date, with the temperature noted that night |
| Requests for an extra blanket | Number of requests per room type |
| Duvet found at the foot of the bed or on the floor | Note from the housekeeping team when servicing the room |
| Appearance of the made bed | Photo after making up: loft, filled corners, drape |
| Handling in the laundry | Duvets per load and actual time until the centre is dry |
At the end, write a one-line rule for purchasing and housekeeping, for example: ‘rooms 101 to 110: 300 g/m²; corner rooms: 400 g/m²; spare blanket in the floor cupboard’.
Washing and reserve: the duvet does not rotate like the cover
The duvet cover is changed at every check-out; the duvet is not. The product sheet for our duvet puts it this way: ‘the filling only needs washing about every 6 months; it is the covers that are washed frequently’. Its care instructions are machine wash at a maximum of 40 °C, tumble dry on low heat only, do not bleach and do not iron. Do not put it back on the bed until the centre is completely dry.
That is why you need few spare duvets, but some for each size: a stained duvet takes time to wash and dry, and in the meantime the bed cannot be made up. Work out how many with the PAR guide, item by item, which treats the duvet separately from the items that rotate at every check-out.
Frequently asked questions
Is a 300 g/m² duvet suitable all year round?
In a heated room, yes: that is the use the product sheet gives for this weight. In summer, with air conditioning or hot nights, it may be too much; in that case many properties remove the duvet and leave the cover or a flat sheet.
What size of duvet does a 160 bed take?
The 260 × 220 cm, the same as the 180 and 200 beds. The duvet cover is also ordered in 260 × 220.
Is a 250 g/m² duvet with a blanket better than a 400 g/m² one?
In rooms where it is cold only on some nights, yes, it usually works better: the guest adds or removes a layer. In a room that gets cold every night, the 400 g/m² simplifies the housekeeping work and avoids relying on the guest finding the blanket.
In summary
Choose the weight by the room you have measured, not by the season; prefer warmth the guest can add to warmth they cannot remove; order the duvet by the width of the mattress and the cover by the duvet, and keep the number of weights as low as possible. With a short trial and a written rule, the next replacement will be a repeat order, not a new decision.
Sources
- Effects of thermal environment on sleep and circadian rhythm — Okamoto-Mizuno and Mizuno, Journal of Physiological Anthropology, 2012
- A study on the thermal comfort in sleeping environments in the subtropics: measuring the total insulation values for the bedding systems commonly used in the subtropics — Lin and Deng, Building and Environment, 2008
- Characterization of the thermophysiological comfort of duvets in consideration of the bed cave — Wölfling and Classen (Hohenstein), Communications in Development and Assembling of Textile Products, 2020
- Sleep comfort: test criteria for duvets — Hohenstein, accessed in 2026