Stand in front of a wall of turnout rugs marked 0g, 100g, 200g and it's easy to feel like you need a translator. Most owners get there eventually by trial and error — a shivering horse one week, a sweaty one the next — but there's a much quicker way to get it right first time, and it starts with understanding what "fill weight" is actually measuring.
This guide walks through what a turnout rug is built to do, what the different fill weights mean in practice, and how to work out what weight turnout rug your own horse needs as the seasons shift.
Table of Contents
What Is a Turnout Rug?
A turnout rug is an outdoor rug built to keep a horse warm, dry and comfortable while they're turned out in a field, whatever the weather's doing. Unlike a stable rug, which only has to manage warmth indoors, a turnout rug needs to cope with rain, wind, mud and general field life — so the outer fabric is tougher, usually a ripstop polyester rated in denier (the higher the number, the more resistant it is to tears and rubs from fences, other horses, or an enthusiastic roll in the mud).
Underneath that tougher outer shell, a good turnout rug combines a waterproof coating — often measured by hydrostatic head rating — with a breathable lining that lets sweat and moisture escape rather than trapping it against the coat. Turnout rugs also come in different cuts and neck styles, from standard neck to combo neck with a detachable cover, along with fastenings like cross surcingles and leg straps that keep everything secure as the horse moves, grazes or rolls. But when it comes to keeping your horse at a comfortable temperature, it's the fill weight doing the real work.
Understanding Turnout Rug Fill Weight
Fill weight refers to the grams of insulating fill packed between a rug's outer shell and its inner lining, expressed in grams — 0g, 50g, 100g, 200g and so on. It's worth stressing that this figure has nothing to do with the physical size of the rug. A 100g rug in a 6'3" fits the same horse as a 0g rug in a 6'3"; fill weight is purely about warmth, not size.
A quick way to think about it: fill weight is your horse's duvet tog rating. The size of the rug is fitted to the horse, but the fill weight is chosen based on the temperature — and how much natural insulation your horse already has.
Turnout Rug Weights Compared
So, what weight is a medium turnout rug? In the UK, 100g fill is generally considered medium weight — the single most popular fill weight sold, and a sensible do-it-all default for an average British winter on an unclipped or lightly-clipped horse. Here's how all four main weights compare:
| Fill Weight | Best For | Typical Horse & Conditions |
|---|---|---|
| 0g (rain sheet) | Waterproofing with no added warmth | Spring/summer, wet-but-mild days, horses with a full natural coat |
| 50g (lightweight) | A light layer of extra warmth | Cool autumn nights, changeable weather, unclipped horses |
| 100g (medium weight) | All-round winter protection | Average UK winter, unclipped or lightly-clipped horses |
| 200g–300g (heavyweight) | Serious cold-weather insulation | Cold snaps, fully clipped, older or thin-skinned horses |
Heavyweight rugs in particular tend to earn their keep with fully clipped horses, older horses, and those who are naturally more sensitive to low temperatures. Some owners also choose a heavyweight rug deliberately, to help a horse hold condition through winter without needing as much extra hard feed to stay warm.
What Weight Turnout Rug Do I Need?
Working out what weight turnout rug you need really comes down to three questions:
- Is my horse clipped? A fully clipped horse has lost a significant amount of its natural insulation and will typically need one weight class higher than an unclipped horse facing the same conditions.
- What's the weather actually doing? Don't just look at today — check the week ahead. A single cold night doesn't call for the same rug as a sustained run of cold, wet weather.
- How does my horse usually cope with the cold? Older horses, those carrying less body condition, and naturally thin-skinned or finer-coated types often need more warmth than a hardy native breed turned out in the same field.
If you're genuinely unsure which way to go, it's generally safer to layer a lightweight rug or fleece under a turnout rug than to invest in one very heavy rug outright — layering gives you far more flexibility as autumn slides into winter and the weather keeps changing.
Frequently Asked Questions
Can you put a fleece or stable rug under a turnout rug?
Yes — this is a common way to add extra warmth on particularly cold nights without buying an entirely separate heavyweight turnout rug. Just check the turnout rug is cut generously enough to fit comfortably over the top without rubbing at the shoulders or withers.
Can you put a turnout rug on a wet horse?
Where possible, towel-dry your horse first. But a breathable turnout rug is designed to let moisture escape, so rugging a slightly damp horse won't cause any harm.
Do turnout rugs stretch?
Most turnout rugs are made from ripstop polyester, which holds its shape well and isn't designed to stretch. That's exactly why getting an accurate size measurement matters far more with a turnout rug than it would with a stretchy fabric — see our guide to measuring a horse for a rug if you're not sure where to start.
How do I know if my turnout rug is too heavy?
Watch for sweating under the rug, particularly around the shoulders and chest, or a damp coat when you remove the rug on a mild day. If you spot this regularly, it's a clear sign to drop down a weight.
Final Thoughts
Once you've got fill weight straight, choosing between 0g, 50g, 100g and heavyweight stops being guesswork and becomes a genuinely useful tool — one that changes with the season, your horse's clip, and how well they cope with the cold. Getting the fit right matters just as much as the weight, so it's worth reading our rug measuring guide alongside this one. And if you're weighing up rain protection versus insect protection for the in-between months, our guide on whether fly rugs are waterproof covers that overlap in more detail.
You can browse our current range in the turnout rugs collection now.
Shop by weight: 50g Turnout Rugs · 100g Turnout Rugs · 200g–300g Turnout Rugs · Heavyweight Turnout Rugs
(The weight-specific links above are still placeholders — swap in the live B2C sub-collection URLs once that range is published. The main collection link is live.)