Sandals Size Calculator

How to calculate sandals size

Sandals sizing starts with foot length, not with the size you wore last time. Measure both feet in the evening, barefoot, and use the longer foot. Trace each foot on paper, measure from the back of the heel to the tip of the longest toe, and measure across the ball for width. The calculator compares that length with broad general ranges and returns the US women's size whose range contains it.

Width, arch, strap style and footbed then shape the final choice, because a foot that is wide or has a high arch can feel tight in the size its length points to. The calculator asks for width and arch height so its guidance changes with your answers, and it asks for strap style and footbed so the comfort guidance changes too. A starting size is only useful when it comes with that context.

Do not choose sandals size from foot length alone

Foot length alone misses the parts of a sandal that fail first. Width decides whether the foot sits on the footbed or hangs over its edge, arch height decides whether a contoured footbed will support or press, and strap style decides whether the foot stays put. If your width points to a wider fit than your length suggests, look for a wide width version before you size up the whole sandal.

Strap style matters just as much. An ankle strap holds the heel down, a toe post holds the front of the foot, and a slide relies on a snug fit across the ball. The calculator uses strap style for that comfort guidance, and it compares your arch with the footbed you chose, so a high arch with a flat footbed gets a different note from a medium arch with a contoured footbed.

General sandals size chart

The chart below gives broad general women's sandals sizes from US 5 to US 12, with foot length in inches and UK and EU equivalents. Treat these as starting ranges, not as brand sizes. Always check the brand chart for the sandals you are buying.

If your foot length falls below US 5 or above US 12, the chart cannot give you a precise starting size. In that case, use the nearest end of the chart as a rough guide and rely on the brand chart and the stated insole length instead.

How width and arch change the choice

A foot under the average width is narrow, a foot near the average is regular, and a foot over the average is wide, as a rough guide. A narrow foot suits a narrow width or an ankle strap, a wide foot needs a wide width or adjustable straps across the ball, and a regular foot should fit a standard width. When the width is wrong, the foot hangs over the footbed edge or slides sideways inside the straps, even when the length is right.

Arch height changes the footbed you can wear comfortably. A low arch can roll inward on a flat footbed, so a contoured footbed helps. A high arch is already raised, so a very high contour can press into it. A medium arch is the most flexible, and most footbed shapes feel comfortable with it.

How strap style changes the choice

Strap style changes where your foot is held. An ankle strap holds the heel down and suits a foot that slips at the back, a toe post holds the front of the foot and suits a foot that likes an open feel, a slide relies on a snug fit across the ball and suits a quick trip, and a gladiator spreads the hold across several straps and suits a long walk. Comfort falls when the strap holds the wrong part of the foot, so match the style to where your foot slips.

Adjustable straps change the fit through the day, which is why they suit warm weather and long walks. Feet swell in heat and after hours of standing, so a strap that fits in the morning can feel tight by evening. A hook and loop or buckle closure lets you loosen the straps when that happens, while a fixed strap gives you no such room.

How footbed shape changes comfort

Footbed shape changes how your weight spreads across the foot. A flat footbed suits a medium arch and a short walk, a contoured footbed supports a low or high arch with a raised area under the arch, and a wedge footbed raises the heel a little and shifts weight forward onto the ball. At the same length, a contoured footbed will feel more supportive than a flat one, and a wedge will feel higher than either.

Choose the footbed for the day as well as the foot. A flat footbed suits a short trip, a contoured footbed suits a long day of walking, and a wedge suits a short outing where you want a little height. The right footbed can make a sandal in the right size feel comfortable all day, while the wrong one can ache within an hour.

Signs sandals are too small

• The toes reach or hang over the front edge of the footbed.
• The straps dig in and leave a red line after a short walk.
• The heel hangs over the back edge of the footbed.
• The arch aches within minutes of putting the sandals on.

Signs sandals are too large

• The heel lifts clear of the footbed with each step.
• The foot slides forward and the toes reach the front edge.
• The straps feel loose and the foot moves sideways inside them.
• There is a large gap of empty footbed behind the heel.

How to choose sandals size online

Shopping online removes the fitting room, so measurements matter even more. Take fresh foot length and width measurements, use the calculator for a starting size, then open the brand chart and compare your numbers with the full row for that brand, not just the size letter. If the brand also lists insole length, compare that too, especially if you are choosing a slide or a toe post sandal where a small length error shows at once.

Read the strap style, footbed shape and heel cup on the product page as well as the chart. A brand that describes a style as a narrow slide has already built a snug forefoot and no back strap into its sizes, so sizing down on top of that can leave you with sandals that pinch at the straps and slip at the heel.

Common sandals sizing mistakes

• Choosing by your usual size letter without checking the brand chart.
• Measuring in the morning and then wearing the sandals all evening.
• Using foot length alone and ignoring width, arch, straps and footbed.
• Sizing up to fix a tight strap, which adds length at the heel too.
• Copying a closed shoe size to an open toe sandal without checking the fit.