Fleece Weights
The 100–300 and R scales: choosing fleece by weight
Fleece earns its place in cold weather by trapping body heat in its loft, and fleece weight is the shorthand for how much loft — and therefore warmth — a jacket carries. Two scales dominate: the Polartec scale of 100 (lightweight), 200 (mid-weight) and 300 (heavy-weight), and Patagonia's R scale, where R1 is lightweight, R2 mid-weight, R3 heavyweight and R4 a hybrid. On both scales the logic is the same: the higher the number, the higher the loft, the warmer and heavier the jacket. This page explains what each weight does best and links to the makers behind the scales.
The main benefit of fleece is its effectiveness at trapping body heat and sustaining the warmth. The synthetic fabric is generally made out of polyester. Polyester is a man-made material composed of two petroleum products that can be manufactured from recycled plastic.
Fleece Weights:
Polartec Scale: 100 lightweight, 200 mid-weight, 300 heavy-weight.
Patagonia Scale: R1 lightweight, R2 mid-weight, R3 heavy weight, R4 is a hybrid (see below).
Fleece “weight” refers to the loft and thickness of the material used in a jacket's construction, and two common scales exist for describing fleece weights. Most companies use the Polartec scale of 100, 200, 300—the higher the number, the higher the loft of the fleece, and the warmer (and heavier) the jacket will be. Fleece jackets with 100-weight ratings are lightweight, highly breathable, offer the wearer a wide range of movement, and work great as light layering pieces for aerobic activities or warmer conditions. Jackets with 200-weight ratings represent the middle ground in fleece, and this tends to be the most popular weight due to its versatility and ease of layering under hardshells. A 300-weight fleece is significantly loftier and heavier, more difficult to layer, and generally designed with cold or extreme weather conditions in mind.
- Polartec® was the first to knit, nap, and shear synthetic yarns into thermal fabric for outdoor apparel. Polyester fibers were engineered for more versatile durability. With greater resiliency, lightweight warmth and fast dry times, Polartec® fleece remains the industry standard for outerwear performance. Polartec® fleece comes in Micro, 100, 200 and 300 weights.
Patagonia developed its own scale for describing fleece weights: R1 to R4. R1 to R3 roughly correspond to the 100 to 300 Polartec scale, whereas R4 is a hybrid fleece combining an R2 grid fleece with a Polartec Windbloc polyester.
- Grid fleeces feature a grid pattern on the inside face of the jacket that facilitates air circulation and moisture wicking. Most grid fleeces have a smooth, bonded or woven outer face that resists pilling, increases wind-resistance, and makes for a versatile compromise between a traditional fleece jacket and a softshell.
What about weights in grams per square meter? This is not an exact science, if you need official weights consult with the fabric supplier or clothing manufacturer. Below is a general estimate as a guide.
- <100 gsm Ultra-light
- 100 – 200 gsm Lightweight
- 200 – 300 gsm Mid-weight
- >300 gsm Heavyweight
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Matching the Weight to the Job
A 100-weight fleece is a breathability tool: thin, highly mobile and easy to layer, it suits high-output activity and mild cold, and it dries fast when worked hard. The 200-weight is the generalist — the weight most people picture as a fleece jacket — balancing warmth, movement and layering room for everyday cold. At 300, fleece becomes a warmth specialist: maximum loft for stationary or very cold use, but bulky under a shell and often too warm for exertion. Choosing between them is really choosing how the jacket will be used, and many outdoor wardrobes honestly need two of the three rather than one compromise worn everywhere.
Weight Is Loft, Not Magic
Fleece weight describes the material's loft and thickness, and warmth follows loft because still air trapped in the pile does the insulating. Wind, however, passes through ordinary fleece easily, so the same jacket that feels warm on a calm day can feel thin on a ridge — which is why fleece is so often paired with a windproof shell, and why wind-block versions exist. The fabric is generally polyester, a synthetic that can be manufactured from recycled plastic, and it keeps insulating when damp far better than cotton or down equivalents, one more reason the weight scales on this page have become the common language for comparing jackets across brands.
Common Questions
What do fleece weights 100, 200 and 300 mean?
On the Polartec scale, 100 is lightweight, 200 is mid-weight and 300 is heavy-weight; the higher the number, the higher the loft and the warmer — and heavier — the jacket.
What is the difference between the Polartec and Patagonia fleece scales?
Both rank fleece by loft and warmth: Patagonia's R1 is lightweight, R2 mid-weight, R3 heavyweight and R4 a hybrid, paralleling the 100/200/300 steps.
Which fleece weight is best for active use in mild cold?
A lightweight 100-weight (R1-style) fleece: it is highly breathable, offers a wide range of movement and layers easily, working best where warmth needs are moderate and activity is high.