Fleece Is Sold by Weight, and the Number Is in the Name
Polartec's 100, 200 and 300 names come from grams per square metre. What each grade handles, where grid fleece fits, and how to size one over a base layer.
The return note that arrives every October is almost always the same: too warm. The jacket is usually a 300-weight fleece bought for a 50-degree commute. Nothing on the hangtag explained that 300 was the heaviest grade in the line, so the buyer reasonably assumed a bigger number meant a better jacket.
It does not. It means a thicker one.
The name is a metric weight
Polartec’s Classic line is named after its fabric weight in grams per square metre. Classic 100 sits near 100 g/m², which converts to roughly 2.9 ounces per square yard. Classic 200 is about 200 g/m², or 5.9 ounces. Classic 300 lands near 300 g/m², or 8.8 ounces.
Those conversions matter because American catalogs often print ounces while the product name carries the metric number. A jacket labeled “300” and a spec sheet reading “8.8 oz” are describing the same cloth, which is a useful thing to know before you decide one listing is heavier than another.
Weight is not the same as warmth, but in one fabric family it is close enough to plan around. The heavier the fleece, the more air it traps and the less it breathes.
What each grade is for
| Grade | Roughly | Works best at | Fails at |
|---|---|---|---|
| 100 | 2.9 oz/yd² | 55–65°F, moving | Standing still below 50°F |
| 200 | 5.9 oz/yd² | 40–55°F, with a base layer | Indoors, or uphill |
| 300 | 8.8 oz/yd² | 30–45°F, low output | Any kind of climbing |
Think of the bands as active temperatures, not standing-around temperatures. A 200-weight fleece at 45°F is comfortable on a walk and too much on a bike ride, because your body is producing heat the fabric is designed to hold.
The three-jacket system for 40 to 70 degrees puts fleece in the middle band for exactly this reason: it can be dumped the moment you warm up.
Grid fleece sits off to the side
Grid fleece, sometimes called power grid, is not a fourth weight so much as a different construction. The inner face is knit in a waffle pattern, so the high points touch your skin and the channels between them move moisture and air. Most grid fleeces land between 5 and 7 ounces per square yard, close to a 200 in warmth, with far more breathability.
That trade is worth naming. A grid fleece is the better midlayer for anything with a pulse and the worse one for standing on a platform in February. For cold and static, a flat 300 wins without argument. For down versus synthetic insulation, the same logic about output applies.
Cut matters more than the grade
A fleece is a midlayer, so it has to slide over something. Look for two to four inches of chest ease over the base layer you actually wear, measured flat and doubled against the chart. Less than that and the fleece compresses the wool beneath it, which defeats both layers.
Sleeves are the second check. A fleece sleeve should end at the wrist bone with the cuff ribbing just covering it, and it should not bunch at the elbow when you bend your arm. Raglan sleeves, which run from underarm to collar with no shoulder seam, are more forgiving under a shell than set-in sleeves. That is a construction detail, not a style preference, and it is why so many technical midlayers use it.
Five minutes, one mirror
Put the fleece on over the base layer and the shell you plan to wear. Reach both arms overhead. The hem should stay near your waistband rather than riding up past it, and the cuffs should stay at the wrist rather than pulling back two inches.
Then drop your arms and look at the front. If the fabric pulls into a horizontal crease across the chest, the fleece is too small for the stack, no matter what the tag says. If it hangs in loose folds from the armpits, it is a size too big and will trap cold air instead of warm.
Both are returns waiting to happen. Neither is fixed by going up or down a grade, which is the point: pick the weight for the temperature, then pick the fit for the layers you own. A 200 that fits over your base layer beats a 300 that does not, every cold morning of the year.
If the base layer is the part you have not sorted yet, start with merino versus cotton before spending on the fleece.
FAQ
- What does the number on a Polartec fleece mean?
- It is the fabric weight in grams per square metre. Classic 100 is about 100 g/m² (2.9 oz/yd²), Classic 200 about 200 g/m² (5.9 oz/yd²), and Classic 300 about 300 g/m² (8.8 oz/yd²). The grade describes the cloth, not the cut, so two 200-weight jackets can fit very differently.
- Is a 200 or 300 fleece warmer for winter?
- 300 is warmer per square metre, but only if it fits over what you wear underneath. A 200-weight fleece with room for a wool base layer and a shell often beats a tight 300 that compresses the layer below it. Warmth in a stack depends on trapped air, not on the heaviest single piece.
- Can you wear a 300-weight fleece indoors?
- Briefly, in a cold room. It is built for standing around below 45°F or for wearing under a shell. Once you start moving at room temperature, the same fabric that kept you warm on a platform will have you carrying it within fifteen minutes.
Written by
Nora Finch
I started Dressing Time after one too many orders that came back in the wrong size. Everything here is built from published specifications, brand measurement charts and what owners actually report.
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