Sizing Information
Find Your Perfect Geekmas Fit
We want your Christmas jumper to look and feel great, so please check our size guide before ordering.
Important Sizing Notice
⚠️ Our jumpers may run slightly smaller than standard UK sizing.
For a comfortable fit, especially if you prefer a relaxed Christmas jumper feel or plan to wear layers underneath, we recommend ordering one size up from your usual size.
How to Measure
Chest
Measure around the fullest part of your chest, keeping the measuring tape level and comfortable.
Shoulders
Measure straight across from one shoulder seam to the other.
Sleeve Length
Measure from the shoulder seam down to the end of the cuff.
Garment Length
Measure from the highest point of the shoulder down to the bottom hem.
SIZE GUIDE (CM)
Size Shoulder Chest Length Sleeve
XS 38 94 60 56
S 40 98 62 58
M 42 102 64 60
L 44 106 66 61
XL 46 110 68 62
2XL 48 114 70 64
3XL 50 118 72 66
4XL 52 122 74 68
5XL 54 126 76 70
Sizing Tips
✅ Between sizes? Choose the larger size.
✅ Looking for a relaxed festive fit? Go one size up.
✅ Planning to wear a shirt or base layer underneath? Go one size up.
✅ Compare the measurements above with a similar jumper
you already own for the most accurate fit.
Please Note
All measurements are taken manually and may vary by 1-2 cm. This is considered normal and does not indicate a manufacturing defect.
If you're unsure which size to choose, our customer support team will be happy to help before you place your order.