Flex2Fit - Size & Fit Guide

Boot calf & shaft size guides
Tap a style to see its size guide. For knee-high boots, wrap a soft tape measure around the fullest part of your calf while standing. For ankle boots, measure around your leg where the top of the boot would sit. Then compare it with your size.
Calf width guide
Misty Fit Info
The calf widens by 1.5cm with every size, so there's more room the further up you go.
| EU size | UK size | Calf (cm) |
|---|---|---|
| 37 | 4 | 35.5 |
| 38 | 5 | 37.0 |
| 39 | 6 | 38.5 |
| 40 | 7 | 40.0 |
| 41 | 8 | 41.5 |
| 42 | 8.5 | 43.0 |
| 43 | 9 | 44.5 |
| 44 | 9.5 | 46.0 |
How to measure: Wrap a soft tape measure around the fullest part of your calf while standing, then compare it with your size above. Measurements are approximate.
Shop Misty →Calf width guide
Maddie Fit Info
A stretch suede calf that stays fairly consistent across sizes, and gives a little more than the measurements below.
| EU size | UK size | Calf (cm) |
|---|---|---|
| 37 | 4 | 35.5 |
| 38 | 5 | 36.0 |
| 39 | 6 | 36.5 |
| 40 | 7 | 37.0 |
| 41 | 8 | 37.5 |
| 42 | 8.5 | 38.0 |
| 43 | 9 | 38.5 |
| 44 | 9.5 | 39.0 |
How to measure: Wrap a soft tape measure around the fullest part of your calf while standing, then compare it with your size above. If you're just over, the stretch suede should give you the extra room.
Shop Maddie →Shaft size guide
Idris Fit Info
The shaft gets 0.5cm taller and 0.5cm wider with every size.
| EU size | UK size | Shaft height (cm) | Shaft circumference (cm) |
|---|---|---|---|
| 36 | 3.5 | 14.0 | 22.0 |
| 37 | 4 | 14.5 | 22.5 |
| 38 | 5 | 15.0 | 23.0 |
| 39 | 6 | 15.5 | 23.5 |
| 40 | 7 | 16.0 | 24.0 |
| 41 | 8 | 16.5 | 24.5 |
| 42 | 8.5 | 17.0 | 25.0 |
| 43 | 9 | 17.5 | 25.5 |
| 44 | 9.5 | 18.0 | 26.0 |
How to measure: Wrap a soft tape measure around your leg where the top of the boot would sit, then compare it with the circumference for your size above. Measurements are approximate.
Shop Idris →Shaft size guide
Immy Fit Info
The shaft gets 0.5cm taller and 0.5cm wider with every size.
| EU size | UK size | Shaft height (cm) | Shaft circumference (cm) |
|---|---|---|---|
| 36 | 3.5 | 12.5 | 22.0 |
| 37 | 4 | 13.0 | 22.5 |
| 38 | 5 | 13.5 | 23.0 |
| 39 | 6 | 14.0 | 23.5 |
| 40 | 7 | 14.5 | 24.0 |
| 41 | 8 | 15.0 | 24.5 |
| 42 | 8.5 | 15.5 | 25.0 |
| 43 | 9 | 16.0 | 25.5 |
| 44 | 9.5 | 16.5 | 26.0 |
How to measure: Wrap a soft tape measure around your leg where the top of the boot would sit, then compare it with the circumference for your size above. Measurements are approximate.
Shop Immy →Shaft size guide
Rafe Fit Info
The shaft gets 0.5cm taller and 1cm wider with every size.
| EU size | UK size | Shaft height (cm) | Shaft circumference (cm) |
|---|---|---|---|
| 36 | 3.5 | 12.5 | 21.0 |
| 37 | 4 | 13.0 | 22.0 |
| 38 | 5 | 13.5 | 23.0 |
| 39 | 6 | 14.0 | 24.0 |
| 40 | 7 | 14.5 | 25.0 |
| 41 | 8 | 15.0 | 26.0 |
| 42 | 8.5 | 15.5 | 27.0 |
| 43 | 9 | 16.0 | 28.0 |
| 44 | 9.5 | 16.5 | 29.0 |
How to measure: Wrap a soft tape measure around your leg where the top of the boot would sit, then compare it with the circumference for your size above. Measurements are approximate.
Shop Rafe →Shaft size guide
Cora Fit Info
The shaft gets 0.5cm taller and 0.5cm wider with every size.
| EU size | UK size | Shaft height (cm) | Shaft circumference (cm) |
|---|---|---|---|
| 36 | 3.5 | 16.5 | 23.0 |
| 37 | 4 | 17.0 | 23.5 |
| 38 | 5 | 17.5 | 24.0 |
| 39 | 6 | 18.0 | 24.5 |
| 40 | 7 | 18.5 | 25.0 |
| 41 | 8 | 19.0 | 25.5 |
| 42 | 8.5 | 19.5 | 26.0 |
| 43 | 9 | 20.0 | 26.5 |
| 44 | 9.5 | 20.5 | 27.0 |
How to measure: Wrap a soft tape measure around your leg where the top of the boot would sit, then compare it with the circumference for your size above. Measurements are approximate.
Shop Cora →Shaft size guide
Babette Fit Info
The shaft gets 0.5cm taller and 0.5cm wider with every size.
| EU size | UK size | Shaft height (cm) | Shaft circumference (cm) |
|---|---|---|---|
| 36 | 3.5 | 25.5 | 30.5 |
| 37 | 4 | 26.0 | 31.0 |
| 38 | 5 | 26.5 | 31.5 |
| 39 | 6 | 27.0 | 32.0 |
| 40 | 7 | 27.5 | 32.5 |
| 41 | 8 | 28.0 | 33.0 |
| 42 | 8.5 | 28.5 | 33.5 |
| 43 | 9 | 29.0 | 34.0 |
| 44 | 9.5 | 29.5 | 34.5 |
How to measure: Wrap a soft tape measure around your leg where the top of the boot would sit, then compare it with the circumference for your size above. Measurements are approximate.
Shop Babette →How to measure your feet
All of our footwear is made with a wider toe box. Some styles are wide (EE) width and others extra wide (EEE) width. As our footwear is made in Spain, our sizes follow the EU sizing structure. If you are unfamiliar with EU sizes or foot widths, these two simple measurements will help you find the right shoe size and the right width.
1. Measure your foot length. Stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe and measure from the wall to the mark. Find that length in the chart below to see which EU shoe size you need.
2. Measure your foot width. While standing, wrap a soft tape measure around the widest part of your foot, across the joint at the base of your big toe. Compare it with the Wide EE and Extra-Wide EEE figures for your size to see which width suits you.
If your foot is noticeably wider or slimmer than the figures for your size, the shoe may feel too tight or too loose.
| EU size | UK size | Foot length (mm) | Wide EE width (cm) | Extra-Wide EEE width (cm) |
|---|---|---|---|---|
| 36 | 3.5 | 229.5 | 22.0 | 22.5 |
| 37 | 4 | 236 | 22.5 | 22.8 |
| 38 | 5 | 242.5 | 23.2 | 23.7 |
| 39 | 6 | 249 | 24.1 | 24.5 |
| 40 | 7 | 255.5 | 25.0 | 25.5 |
| 41 | 8 | 262 | 26.0 | 26.5 |
| 42 | 8.5 | 268.5 | 26.5 | 27.0 |
| 43 | 9 | 275 | 27.0 | 27.5 |
| 44 | 9.5 | 281.5 | 27.5 | 28.0 |
Fine-tune the fit
Every Flex2Fit style has two insole components: a layer of soft padding (removable with some styles) and a removable contoured footbed. Adapt the fit to suit you by removing one or both insoles to create a wider, deeper fit, or swap it for your own custom orthotic.
Quick questions
I am between two sizes. Which should I choose?
Fit varies by style: some come up generous and some a little small. Please check the individual product pages for specific guidance on sizing up or down.
Can I take the footbed out?
Yes. The moulded footbed lifts out for a deeper toe box and a wider fit, or you can replace it with your own custom orthotic. The foam layer underneath stays in.
Do Flex2Fit styles have the bunion panel?
No, Flex2Fit styles do not have the bunion panel found elsewhere in our range.
What if they do not fit?
We offer free UK returns within 28 days of delivery.
Still not sure?
Email us your measurements at help@sargassoandgrey.com, and we would be very happy to help you choose.







