Quick Answer: For most Canadian homes with central heating, an all-season duvet with 300 to 400 GSM fill weight works year-round. Summer duvets use 150 to 250 GSM. Winter duvets use 450 to 600+ GSM. The right weight depends on your bedroom temperature, sleep habits, and whether you run hot or cold at night.
In This Guide
Reading Time: 10 minutes
Understanding Duvet Weight: GSM, Tog, and Fill Power
Three different measurement systems describe duvet warmth in Canada, and they all measure different things. Understanding the difference saves you from buying a duvet that is too hot or too thin for your needs.
GSM (Grams per Square Metre)
GSM measures the weight of the filling inside the duvet per square metre. It tells you how much fill material is in the duvet, which directly correlates with warmth. Higher GSM means more fill, which generally means more warmth.
GSM Quick Reference
- 150 to 250 GSM: Lightweight / summer
- 250 to 350 GSM: Mid-weight / spring and fall
- 300 to 400 GSM: All-season (most popular in Canada)
- 450 to 600 GSM: Winter weight
- 600+ GSM: Heavy winter / unheated rooms
GSM is the most common measurement you will see on Canadian duvet labels. It is straightforward: more grams means more filling means more warmth. However, GSM alone does not tell the full story because different fill types provide different amounts of insulation per gram.
Tog Rating
Tog (Thermal Overall Grade) is a British measurement system that rates the thermal resistance of a duvet, essentially how well it retains heat. Unlike GSM, tog measures actual warmth performance rather than fill quantity.
| Tog Rating | Warmth Level | Best For |
|---|---|---|
| 1 to 4.5 | Lightweight | Summer, hot sleepers, warm bedrooms |
| 4.5 to 7 | Light-medium | Spring/fall, mild temperatures |
| 7 to 10.5 | Medium | All-season in heated homes |
| 10.5 to 13.5 | Warm | Canadian winters, cool bedrooms |
| 13.5 to 15 | Extra warm | Very cold rooms, no central heating |
Tog ratings are less common on Canadian product labels than GSM, but some European and British brands sold in Canada use this system. If you see a tog rating, the chart above translates it into practical terms.
Fill Power (For Down Duvets)
Fill power measures the loft (fluffiness) of down clusters. It indicates how much space one ounce of down occupies in cubic inches. Higher fill power means the down traps more air, providing more insulation with less weight.
- 400 to 500 fill power: Basic, heavier for the same warmth
- 550 to 650 fill power: Good quality, balanced weight and warmth
- 700 to 800 fill power: Premium, warm yet lightweight
- 800+ fill power: Luxury, maximum warmth with minimum weight
Fill power only applies to down duvets. A 700 fill power down duvet at 300 GSM will be warmer than a 500 fill power down duvet at 300 GSM, even though both have the same amount of fill by weight. The higher fill power down creates larger air pockets that trap more heat.
Dorothy, Sleep Specialist: "I tell customers to think of GSM as the quantity of fill and fill power as the quality. A great down duvet has both: enough fill to cover you properly and high enough fill power to keep you warm without weighing you down."
8 min read
Seasonal Duvet Weight Chart for Canada
This chart combines GSM, tog, and fill type to give you a practical reference for each season in a typical Canadian home with central heating.
| Season | Months | Down GSM | Wool GSM | Synthetic GSM | Tog Equivalent |
|---|---|---|---|---|---|
| Summer | June to August | 150 to 200 | 200 to 300 | 200 to 300 | 1 to 4.5 |
| Spring/Fall | April to May, Sept to Oct | 250 to 350 | 300 to 400 | 300 to 450 | 4.5 to 7 |
| All-Season | Year-round | 300 to 400 | 350 to 450 | 350 to 500 | 7 to 10.5 |
| Winter | November to March | 400 to 550 | 450 to 600 | 500 to 700 | 10.5 to 13.5 |
| Extreme Cold | Unheated/cottage | 550+ | 600+ | 700+ | 13.5 to 15 |
Notice that synthetic duvets need higher GSM to achieve the same warmth as down or wool. This is because synthetic fibres trap less air per gram than natural fills. A 400 GSM down duvet will be noticeably warmer than a 400 GSM synthetic duvet of the same size.
How Fill Type Affects Warmth
The fill inside your duvet determines how much warmth you get per gram of weight. Here is how the main fill types compare.
Goose Down
The warmest fill per gram. High fill power goose down (700+) creates large, resilient air pockets that trap heat effectively. A lightweight goose down duvet can keep you as warm as a much heavier synthetic one. The trade-off: highest cost, requires careful maintenance, and can trigger allergies in sensitive individuals.
Duck Down
Similar to goose down but with slightly smaller clusters, resulting in lower fill power (typically 500 to 650). Duck down is more affordable than goose down while still offering good warmth-to-weight performance. Many "down duvets" in Canada use duck down unless specifically labelled as goose.
Wool
Wool provides moderate warmth with excellent temperature regulation. It absorbs up to 30% of its weight in moisture without feeling damp, which keeps the sleep microclimate stable. Wool duvets tend to be heavier than down for the same warmth level, but they regulate temperature more actively, making them a strong all-season choice.
Wool's Temperature Advantage
Research published in Nature and Science of Sleep (2016) found that wool bedding helped sleepers maintain more stable core body temperature compared to synthetic materials. Wool duvets actively respond to your body heat and moisture, releasing warmth when you are cold and cooling when you are warm. This makes a single wool duvet viable as an all-season option in ways that down or synthetic cannot match.
Synthetic (Polyester / Microfibre)
Synthetic fills are the most affordable option. Modern microfibre synthetics mimic the loft of down better than older polyester fills. However, they still require more material to match natural fill warmth, resulting in heavier duvets. Synthetic fills also degrade faster, losing loft after 3 to 5 years compared to 10 to 20 years for natural fills.
The advantage: machine washable, hypoallergenic, and available at every price point.
Fill Type Warmth Comparison
| Fill Type | Warmth per Gram | Weight for Same Warmth | Lifespan | Price Range (Queen) |
|---|---|---|---|---|
| Goose down (700+ FP) | Excellent | Lightest | 10 to 15 years | $400 to $1,200 |
| Duck down (500-650 FP) | Very good | Light | 8 to 12 years | $200 to $600 |
| Wool | Good | Medium | 15 to 20 years | $200 to $600 |
| Synthetic microfibre | Moderate | Heaviest | 3 to 5 years | $50 to $200 |
Matching Duvet Weight to Bedroom Temperature
Your bedroom temperature at night is the single most important factor in choosing duvet weight. Here is a practical guide.
Duvet Weight by Bedroom Temperature
- Above 22 C (72 F): Lightweight duvet only (150 to 250 GSM). Or just a flat sheet. Sleeping in a room this warm is actually above what sleep researchers recommend.
- 20 to 22 C (68 to 72 F): Light to mid-weight (200 to 350 GSM). This is the most common Canadian bedroom temperature with summer air conditioning or spring/fall heating.
- 18 to 20 C (64 to 68 F): All-season weight (300 to 450 GSM). This is the range sleep experts consider optimal for sleep quality.
- 16 to 18 C (61 to 64 F): Winter weight (400 to 550 GSM). Common for energy-conscious households that lower the thermostat at night.
- Below 16 C (61 F): Heavy winter weight (550+ GSM). Cottages, poorly insulated rooms, or intentionally cold bedrooms.
The Sleep Foundation and the American Academy of Sleep Medicine recommend bedroom temperatures between 15.5 C and 19.5 C (60 to 67 F) for optimal sleep. At these temperatures, most Canadians need a mid-weight to winter-weight duvet depending on personal warmth preference.
Brantford Bedroom Realities
Most Brantford homes maintain nighttime bedroom temperatures between 18 C and 21 C with central heating in winter. At these temperatures, an all-season duvet (300 to 400 GSM) works for the majority of sleepers year-round. If you lower your thermostat below 18 C at night to save on heating costs, step up to a winter-weight duvet for the coldest months.
Hot Sleeper vs Cold Sleeper Recommendations
Your body's natural temperature regulation matters as much as the room temperature. Research published in the Journal of Physiological Anthropology confirms that individuals vary significantly in thermoneutral zones (the temperature range where the body does not need to actively heat or cool itself during sleep).
If You Sleep Hot
Hot Sleeper Duvet Guide
- Choose a duvet one weight category lighter than the room temperature chart suggests
- Prioritise breathable natural fills (wool is best for temperature regulation, down with high fill power is second)
- Avoid synthetic fills, which trap heat and moisture
- Look for cotton percale covers (breathable) rather than sateen (slightly warmer)
- Consider a lightweight wool duvet year-round, using a flat sheet only in peak summer
- Make sure your mattress breathes too: a heat-trapping mattress makes any duvet feel warmer
If You Sleep Cold
Cold Sleeper Duvet Guide
- Choose a duvet one weight category heavier than the room temperature chart suggests
- High fill power goose down (700+) provides maximum warmth with minimum weight
- Consider a dual-layer system: two thinner duvets clipped together for maximum insulation
- Cotton sateen covers add a slight warmth layer compared to percale
- Flannel duvet covers in winter add noticeable warmth without changing the duvet
- Check that your mattress is not pulling heat away from your body. Innerspring mattresses can feel cooler than memory foam.
Couples with Different Temperature Preferences
This is more common than most people expect. One partner throws off covers while the other wraps up tightly. Solutions include:
- Two single duvets on one bed (Scandinavian method): Each person chooses their own weight. No more tug-of-war.
- Wool duvet: Wool's active temperature regulation can moderate the difference, keeping one side from overheating while keeping the other side warm enough.
- Dual-zone duvet: Some brands offer duvets with different fill weights on each side, though these are less common in Canada.
Brad, Owner, 40+ years of experience: "We hear about the temperature tug-of-war from couples all the time. The Scandinavian two-duvet approach sounds unusual to Canadians, but it works. Two single duvets on a queen bed cost the same as one queen duvet, and both partners sleep at their preferred temperature. It is a simple fix that more people should try."
Duvet Weights by Canadian Climate Zone
Canada's climate varies dramatically by region. Here is a general guide by zone.
| Region | Winter Lows | Summer Highs | Recommended Approach |
|---|---|---|---|
| Southern Ontario (Brantford, Toronto, Hamilton) | -10 to -20 C | 25 to 35 C | All-season duvet (350 to 400 GSM) for most; lightweight option for July/August |
| BC Lower Mainland (Vancouver) | 0 to -5 C | 20 to 30 C | All-season (300 to 350 GSM) year-round |
| Prairies (Calgary, Winnipeg) | -20 to -35 C | 25 to 32 C | Winter weight (450+ GSM) November to March; lightweight for summer |
| Atlantic Canada (Halifax, St. John's) | -5 to -15 C | 20 to 28 C | All-season to winter weight (350 to 450 GSM); damp climate favours wool |
| Northern Canada | -30 to -50 C | 15 to 25 C | Winter weight (500+ GSM) most of the year |
Remember that these recommendations assume standard central heating. If you keep your home cooler at night, go one category heavier. If you heat your bedroom above 21 C, go one category lighter.
Practical Buying Tips
Before You Buy
- Check the label for GSM, not just "warm" or "lightweight." Vague warmth descriptions vary between brands. GSM is a measurable standard.
- For down, check both fill power AND fill weight. A duvet can have high fill power but be under-filled. You need adequate amounts of quality fill.
- Look for certified fills. DOWNMARK (for Canadian down), RDS (Responsible Down Standard), and GOTS (for organic materials) indicate quality and ethical sourcing.
- Buy a duvet cover. Washing a duvet cover weekly is easier and cheaper than cleaning the duvet itself. Choose breathable cotton or linen.
- Consider the all-season route. One good all-season duvet (350 to 400 GSM in a quality fill) often works better than swapping between summer and winter options in a heated Canadian home.
The Investment Calculation
A quality natural-fill duvet costs more upfront but often costs less per year of use:
| Fill Type | Typical Queen Price | Expected Lifespan | Cost per Year |
|---|---|---|---|
| Synthetic | $80 to $150 | 3 to 5 years | $16 to $50 |
| Duck down | $200 to $400 | 8 to 12 years | $17 to $50 |
| Wool | $200 to $500 | 15 to 20 years | $10 to $33 |
| Goose down (700+ FP) | $400 to $1,000 | 10 to 15 years | $27 to $100 |
Wool often offers the best long-term value when you factor in its 15 to 20 year lifespan and all-season versatility. You can read more about wool options in our Wool Duvet Canada guide.
Talia, Showroom Specialist: "We see the same pattern with mattresses and bedding. Customers who invest a bit more in quality upfront end up spending less over time and sleeping better in the process. A $500 wool duvet that lasts 20 years costs less than buying a $100 synthetic duvet four times."
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Call 519-770-0001Frequently Asked Questions
What GSM is an all-season duvet in Canada?
For most Canadian homes with central heating, an all-season duvet ranges from 300 to 400 GSM depending on the fill type. Down duvets lean toward the lower end (300 to 350 GSM) because down provides more warmth per gram. Synthetic duvets need the higher end (350 to 500 GSM) to match the same warmth level. Wool falls in between.
Is a higher tog rating always warmer?
Yes. Tog measures thermal resistance, so a higher number always means more warmth. A 13.5 tog duvet is warmer than a 7.5 tog duvet regardless of fill type. However, a lightweight high-tog down duvet and a heavy high-tog synthetic duvet can have the same tog rating with very different weights on your body.
Do I need separate summer and winter duvets?
Not necessarily. In a typical heated Canadian home (18 to 21 C at night), a single all-season duvet (300 to 400 GSM) works for most of the year. You might want a lightweight option (under 250 GSM) for the hottest weeks of July and August if you do not have air conditioning. Wool duvets, in particular, work well year-round because they actively regulate temperature.
What does fill power mean for down duvets?
Fill power measures the volume (in cubic inches) that one ounce of down occupies. Higher fill power (700+) means the down creates larger air pockets that trap more heat with less weight. A 700 fill power duvet at 300 GSM will be warmer and lighter than a 500 fill power duvet at the same GSM, because the higher quality down insulates more efficiently per gram.
Can my mattress affect how warm my duvet feels?
Yes. Memory foam mattresses retain body heat, making your duvet feel warmer. Innerspring and hybrid mattresses breathe more, allowing heat to dissipate and making your duvet feel closer to its rated warmth. If you sleep hot on a memory foam mattress, choose a lighter duvet than you otherwise would. The mattress and duvet work as a system.
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Duvets in every warmth level
Each of our Highland Feather duvets comes in Summer, All Season, All Season Warm, and Deluxe fills so you can match the weight to your room.
- Montpellier 700 Loft White Duck Down Duvet, 500TC sateen, 700 loft everyday-luxury pick, from $384
- Grenoble 800 Loft White Duck Down Duvet, 800 loft flagship duck down, 500TC swiss-dot sateen shell, from $466
- Shop all Highland Feather down duvets →, the full goose and duck down range, made in Canada