Click here to learn more about our different fits and how to choose the size that's right for you.
We strive to make all our products true to size. The sizing charts below are general and not garment specific, but hopefully, it will give you some guidance when choosing your size. In instances where you’re perhaps in between two sizes then take a look at our recommendations below.
For further assistance with sizing, contact us here.
If for some reason you are not 100% satisfied with the size you chose, we’ll happily offer an exchange, refund or store credit on any non-sale garments. For more about our refunds and exchange policy, click here.
|
|
XS |
S |
M |
L |
XL |
XXL |
Waist |
Inch |
27 |
28-30 |
32-34 |
36-38 |
40-42 |
44-46+ |
|
cm |
68 - 70 |
71-76 |
81-86 |
91-96 |
101-108 |
111-116+ |
Chest |
Inch |
32-34 |
34-36 |
38-40 |
42-44 |
46-48 |
50+ |
|
cm |
81.5 - 86 |
86-91 |
96-101 |
106-111 |
116-121 |
127+ |
Measurements in cm.
Measurements include ribbed hem.
Sleeve length from pit to hem.
XS |
S |
M |
L |
XL |
XXL | |
Pit to pit |
47.4 |
51.2 |
55 |
58.8 |
62.6 |
66.4 |
Torso Length |
65.9 |
68.5 |
71 |
73.5 |
76.1 |
78.6 |
Sleeve Length |
50.2 |
52.1 |
54 |
55.9 |
57.8 |
59.7 |
Measurements in cm.
Measurements include ribbed hem.
Sleeve length from shoulder to cuff.
XS |
S |
M |
L |
XL |
XXL | |
Pit to pit |
49.4 |
53.2 |
57 |
60.8 |
64.6 |
68.4 |
Torso Length |
68.9 |
71.5 |
74 |
76.5 |
79.1 |
81.6 |
Sleeve Length |
74.2 |
76.1 |
78 |
79.9 |
81.8 |
83.7 |
Outside Leg measurement (including waist band).
S | M | L | XL | XXL | ||
Inside Leg | inch | 29 | 30 | 30.5 | 31 | 31.5 |
cm | 74.5 | 76 | 77 | 78.5 | 80 | |
Outside Leg | inch | 41 | 41.5 | 42 | 42.5 | 43 |
cm | 105 | 106 | 107.5 | 109 | 110 |
Outer leg length measure from top of waist to ankle.
Measurements in cm.
XS | S | M | L | XL | XXL | |
Waist | 58.9 | 64 | 69.1 | 74.2 | 79.2 | 84.3 |
Hips | 68.9 | 74 | 79.1 | 84.2 | 89.2 | 94.3 |
Outer Leg | 90.3 | 93.5 | 96.7 | 99.8 | 103 | 106.2 |
Leg length measurement includes ankle cuff.
XS | S | M | L | XL | XXL | |
Waist | 70.4 | 75.2 | 80 | 84.8 | 85.6 | 94.4 |
Hips | 82.4 | 87.2 | 92 | 96.8 | 101.6 | 106.4 |
Leg Length | 81.6 | 82.3 | 83 | 83.7 | 84.4 | 85.1 |
XS |
S |
M |
L |
XL |
|
Australian |
6-8 |
8-10 |
10-12 |
12-14 |
14-16 |
US |
2-4 |
4-6 |
6-8 |
8-10 |
10-12 |
European |
34-36 |
36-38 |
38- 40 |
40-42 |
42-44 |
The Altitude range is designed to be a tight, but comfortable, fit. If you size up it will give you a little extra room, but it will still hug your body as that’s what this range is designed to do. If you want a looser fit consider the Ultra or Universal range.
XS | S | M | L | XL | XXL | ||
Bust | inch | 30-32 | 32-34 | 34-37 | 37-40 | 40-42 | 42-45 |
cm | 76-82 | 82-88 | 88-94 | 94-100 | 100-107 | 108-114 | |
Waist | inch | 24-26 | 26-28 | 28-30 | 30-32 | 32-35 | 35-38 |
cm | 58-64 | 64-70 | 70-76 | 76-82 | 82-89 | 89-96 | |
Hips | inch | 34-36 | 36–38 | 38-40 | 40-42 | 42-44 | 44-47 |
cm | 84-90 | 90-96 | 96-102 | 102-108 | 108-115 | 115-122 |
These garments are designed true to size, but going up a size in the Ultra will give it a slightly looser fit, whilst remaining sporty. The Universal and Horizon are already designed as a more casual fit.
XS | S | M | L | XL | XXL | ||
Bust | inch | 29.5–32.5 | 32.5–35.5 | 35.5–38 | 38–41 | 41–44.5 | 44.5–48.5 |
cm | 75-82.5 | 82.5-90 | 90-96.5 | 96.5-104 | 104-113 | 113-123 | |
Waist | inch | 23.5–26 | 26–29 | 29–31.5 | 31.5–34.5 | 34.5–38.5 | 38.5–42.5 |
cm | 60-66 | 66-73.5 | 73.5-80 | 80-87.5 | 87.5-94.5 | 97.5-108 | |
Hips | inch | 33–35.5 | 35.5–38.5 | 38.5–41 | 41–44 | 44–47 | 47–50 |
cm | 83.5-90 | 90-97.5 | 97.5-104 | 104 -111.5 | 111.5-119.5 | 119-127 |
Measurements in cm.
Measurements include ribbed hem.
Sleeve length from pit to hem.
XS |
S |
M |
L |
XL |
XXL | |
Pit to pit |
41.4 |
45.2 |
49 |
52.8 |
56.6 |
60.4 |
Torso Length |
60.5 |
63 |
65.5 |
68.1 |
70.6 |
73.2 |
Sleeve Length |
47.9 |
50.5 |
53 |
55.5 |
58.1 |
60.6 |
Measurements in cm.
Measurements include ribbed hem.
Sleeve length from shoulder to cuff.
XS |
S |
M |
L |
XL |
XXL | |
Pit to pit |
44.4 |
48.2 |
52 |
55.8 |
59.6 |
63.4 |
Torso Length |
62.9 |
65.5 |
68 |
70.5 |
73.1 |
75.6 |
Sleeve Length |
68.2 |
70.1 |
72 |
73.9 |
75.8 |
77.7 |
Measurements do not include the ankle cuff.
Please keep in mind the style of these pants is slightly drop crotch.
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL | |
Waist |
72.4 |
77.2 |
82 |
86.8 |
91.6 |
96.4 |
Hip |
98.2 |
104 |
108.8 |
113.6 |
118.4 |
123.2 |
Leg Length |
56.4 | 57.6 | 58.8 | 60 | 61.2 | 62.4 |
Measurements in cm.
Outer Leg Length includes from the top of the waist to the bottom of the pant leg.
XS |
S |
M |
L |
XL |
XXL | |
Waist 1/2 measurement |
34 |
36.5 |
39 |
41.5 |
44 |
46.50 |
Hip 1/2 measurement |
40 |
42.5 |
45 |
47.5 |
50 |
52.5 |
Outer Leg Length |
106.8 | 108 | 109.2 | 110.4 | 111.6 | 112.8 |
Outside leg measurement includes waist band.
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL |
|
Waist |
68.4 |
73.2 |
78 |
82.8 |
87.6 |
92.4 |
Hip |
94.4 |
99.2 |
104 |
108.8 |
112.6 |
118.4 |
Outside Leg |
95.6 |
96.8 |
98 |
99.2 |
100.4 |
101.6 |
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL | |
Waist |
72.4 |
77.2 |
82 |
86.8 |
91.6 |
96.4 |
Hip |
98.2 |
104 |
108.8 |
113.6 |
118.4 |
123.2 |
Leg Length |
60.5 | 63 | 65.5 | 68.1 | 70.6 | 73.2 |
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL | |
Waist |
72.4 |
77.2 |
82 |
86.8 |
91.6 |
96.4 |
Hip |
98.2 |
104 |
108.8 |
113.6 |
118.4 |
123.2 |
Leg Length |
60.5 | 63 | 65.5 | 68.1 | 70.6 | 73.2 |
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL | |
Waist |
72.4 |
77.2 |
82 |
86.8 |
91.6 |
96.4 |
Hip |
98.2 |
104 |
108.8 |
113.6 |
118.4 |
123.2 |
Leg Length |
42.2 | 44.8 | 47.3 | 49.8 | 52.4 | 54.9 |
Measurements in cm.
XS |
S |
M |
L |
XL |
XXL | |
Waist |
72.4 |
77.2 |
82 |
86.8 |
91.6 |
96.4 |
Hip |
98.2 |
104 |
108.8 |
113.6 |
118.4 |
123.2 |
Leg Length |
10.5 | 13 | 15.5 | 18.1 | 20.6 | 23.2 |
All sizes are given in US Sizing
Men's | Women's | |
S | 4 - 6 | 5.5 - 7.5 |
M | 7 - 10 | 8.5 - 11.5 |
L | 11 - 14 | 12 - 15.5 |
Measurement given for bicep width and arm warmer length. Measure around the fullest part of your upper arm in a relaxed position.
Use the chart below to determine your size. If you’re between two sizes, order the smaller size for a tighter fit or the larger size for a looser fit.
Approximate measurements only.
Bicep | Arm Warmer Length | |
XS | 27 - 28 cm | 45 cm |
S | 29 - 30 cm | 46.5 cm |
M | 31 - 32 cm | 48 cm |
L | 33 cm + | 49.5 cm |
Hand Length - Measure from the top of your middle finger to the base of the palm.
Use the chart below to determine your size. If you’re between two sizes, order the smaller size for a tighter fit or the larger size for a looser fit.
Pace Gloves:
S | 16 cm |
M | 18 cm |
L | 20 cm |
To measure your head circumference, take a sewing measuring tape and wrap around your head so that the measuring tape winds just above the ears, in the middle of your forehead and in the centre back of your head.
Use the chart below to determine your size. If you’re between two sizes, order the smaller size for a tighter fit or the larger size for a looser fit. Approximate measurements only.
Head circumference | |
S/M | 50-60 cm |
M/L | 60-70 cm |
For further assistance with sizing, contact us here.
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Our Altitude range was originally designed as a baselayer, to fit close to your body for maximum performance, so it’s snug but soft, with plenty of give for extra comfort. If you’re usually a medium, for example, you might find the medium fits tighter than you’d expect because it’s designed to be ‘contact fit’ and look and feel like a second skin. If you’re looking for a more relaxed fit you might consider sizing up (it will still be relatively snug) or choosing another style.
Not only does the Men's Altitude Base Layer Tee look and feel good, it's alsoincredibly versatile, taking you through a wide range of temperatures and conditions. Wear this Base Layer T-shirt as part of our layer system for extra warmth, and when the temperature rises, you’ve got the perfect lightweight and breathable T-shirt that delivers the comfort and performance you need to go the distance.
(For a more relaxed fit try our Ultra or Universal T-shirts.)
Tag free, flatlock stitching, raglan sleeves eliminate chafe and maximize comfort.
Why you’d buy this: You like your stuff to fit nice and close to your body whether you wear it on its own, or under another layer and don’t want any extra bulk or bunching. You might also want a bit of extra length which this one gives you. It’s super soft and comfy, and 96% merino so it’s super natural which means almost no microplastic issues when you wash it or landfill when you’ve finished with it.
As with all our clothes, the merino delivers natural temperature regulation, breathability, moisture wicking and odour resistance.
Originally designed to be worn as a base layer, (is usually underneath something else), this is a ‘contact fit’ layer so will hug your body. If you don’t want it to fit, feel or look like a second skin, you might try another style, or go up a size, but please note: even going up a size will fit quite close to your body because of the fabric and cut.
New improved fit. Regular body length, shorter than the Altitude long sleeve styles.
True to size.
Model wears size small in rust.
Model wears size medium in forest marle, green, black, and charcoal marle.
Model specs - height 181cm, chest 103cm, waist 81cm (32 inch). Normally wears 32 inch pant, 10-11 size shoe.
Snow sports
Cycling
Running
170gsm lightweight
96% superfine Australian Merino
4% Elastane - for an easy all-way stretch.
A MicroMerino® Fabric.
I am regular user of extra fine merino tshirts for my gym and bike rides. I have had a few different brands. This one was well stitched and styling wise looks great. I found wool to be a little chafey compared to some other brands (not sure what merino fiber grading is this), also I wish they would provide technical info such as weight in grams, and merino grade (how many microns). Also I am not sure if there is any mixed elastin/lucra or another blend fibers added
Hi Tauqeer and sorry to hear you had a chafing issue. That’s super unusual and not something we can remember hearing from any of our customers unless there was something else rubbing - we’d actually really like to know more about where it chafed so we can understand the problem better, and as part of our money back guarantee, if you’re not happy, we will absolutely replace or refund your top no worries at all. Just contact customer service to arrange that. Just so you know, we can confirm the online product description has a fabric tab that shows this top is 96% merino (we only add 4% elastane to give it some extra stretch), and depending on how you are hoping to see weight measured, we supply the standard gsm measurement which is 170gsm. (We don’t weight every size etc, just give the industry standard gsm which is grams per square metre.) As far as microns go, although that is not listed on our fabric description we have a whole page of info about our ‘MicroMerino’ fabrics which explains it’s 18.5 microns which is classified as ‘fine' and on the cusp of ‘superfine' - you’ll find that here: https://iomerino.com/pages/micromerino
- which is about as fine as you can go in clothing like this without starting to compromise durability. Please feel free to contact customer service so we can help you with your top.
Best and most comfortable merino clothing for the UK and Canada winter. A must buy is the base layers. Tops and leggings. Very happy with my purchase.
Easy to care.
Can't wait to use my gear for next trip to Finland 2025.
One of many excellent ioMerino products I've purchased and will continue to do so. These are among the best base layers.
Amazing
To get the right fit I sized up, and it is now part of the summer t-shirts
Very happy with this purchase. Fits well. Well made. And does it’s job. Keeping me warm.
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