How a shoe should fit
- Length. About half an inch (12.7 mm) in front of the longest toe (Royal Devon NHS); Brooks puts it as a thumb’s width beyond the big toe. The longest toe isn’t always the big toe.
- Width. Your toes shouldn’t feel cramped together or make the side of the shoe bulge (Royal Devon), and the widest part of the shoe should match the widest part of your foot, standing (South Tees NHS). Width letters by size
- Depth. Your toes shouldn’t touch the top of the shoe (Royal Devon).
- Heel. The back of the shoe grasps your heel so it doesn’t slide up and down as you walk (South Tees), and a lace, strap or Velcro stops the foot sliding forward (Royal Devon).
- From the start. Don’t accept shoes that need “breaking in” (South Tees): shoes don’t stretch, and if they don’t feel right when you buy them they probably never will (Brannock).
Half sizes
A half size is a small step of foot length, and it differs by system:
So if a whole size is too big and the size below too small, the half size between is about 4 mm either way. Not every shoe comes in halves: Crocs’ clog chart has 0 half sizes in 16 rows, and Dr. Martens’ 2 in 15.
Between two sizes
Our sizes round up: your size is the first one long enough for your foot, so you never get a shoe shorter than your foot. When your foot is within 1.5 mm of the smaller size, the result says so, as that one may fit too.
- The brand’s chart decides. For a men’s US 9, the 23 brands whose charts give foot lengths put it between 26.0 and 27.7 cm, 17 mm apart: the size between two on one brand’s chart may be a clear fit on another’s.
- What brands say. Under Armour and Shimano say to size up between sizes; adidas says a size down if you want a snug fit, up for a looser one.
- Width before length. If the size that fits your length is tight across the foot, a wider fitting adds width without length; a size up adds both.
By type of shoe
- Running shoes
- Half an inch, a thumb’s width, at the toe, and go by the US size of your previous sports shoes, Brooks says. Shoes give in width, but not in length.
- Boots
- Size boots on the brand’s own chart, as any shoe: Timberland’s charts, boots included, put a men’s US 9 at a foot up to 27.0 cm, against 26.25 cm on the standard table. Boot size vs shoe size
- Sandals
- Birkenstock sizes in EU numbers, each covering two US half sizes (EU 42 is a men’s US 9-9.5), and prints a narrow and a regular width. Birkenstock’s chart
- Clogs
- Crocs makes clogs in whole sizes only: between two, its chart decides. Crocs’ chart
- Heels
- Ideally a broad heel no higher than 4 cm: Royal College of Podiatrists advice, on South Tees NHS’s footwear page.
- Kids’ shoes
- At least 6 mm, ideally 10 mm, in front of the longest toe (Evelina London). How much room, and how often to check
- Ski boots and skates
- Sized by the shell, not like shoes. Ski, snowboard and skate sizes
Shoes too big or too small
Too small
- Less than about half an inch in front of the longest toe.
- Toes cramped together, the side of the shoe bulging, or toes touching the top.
Go up a half size, or the same size in a wider fitting if it’s tight across the foot.
Too big
- The heel slides up and down as you walk, which the back of the shoe is there to stop (South Tees).
- The foot slides forward even laced or fastened, which the fastening is there to stop (Royal Devon).
Go down a half size, or a narrower fitting if it’s loose across the foot.
Your size, then the fit
Type your foot length for your size in every system and on each brand’s chart, with a note when you’re near the size below. For width: foot width calculator.
Questions
How much room should be at the end of a shoe?
About half an inch between the longest toe and the end of the shoe: Royal Devon NHS podiatry gives half an inch, and Brooks half an inch, a thumb’s width, from the big toe. For children, Evelina London gives at least 6 mm and ideally 10 mm.
How much bigger is a half size?
In US and UK sizes, 4.2 mm of foot length; in EU sizes 3.3 mm; in Mondopoint and Japanese sizes 5 mm.
Should I size up or down when I’m between sizes?
Our sizes round up, so you never get a size shorter than your foot. Brands differ: Under Armour and Shimano say to size up between sizes, and adidas says a size down if you want a snug fit, up for a looser one. Check the brand’s own chart: for a men’s US 9, brands’ charts differ by 17 mm.
Should I size up if shoes are tight across the foot?
Usually not: on Brannock’s scale, a whole size up adds 3.2 mm of width and 8.5 mm of length, and one width letter 4.8 mm of width and no length. Brands set their own fittings (New Balance’s are 3–4 mm apart), but a wider fitting never adds length. Try the same size in a wider width.
Will tight shoes stretch?
Don’t count on it. Brannock’s fitting tips say shoes don’t stretch: if they don’t feel right when you buy them, they probably never will. South Tees NHS podiatry says not to accept shoes that need “breaking in”, and Brooks that shoes give in width, but not in length.