TTS stands for True to Size. In a sneaker review, it means the model fits close to the reference size used by the reviewer. That reference might be their usual size in the brand or the size recommended by its official chart.
TTS is a starting point for choosing a size. Width, instep height, toe shape, socks, and fit preferences can lead two people to choose different sizes in the same model.
Does TTS mean always wearing the same size?
No. TTS keeps the same meaning, but the reference size can change between brands and models. You may wear one size in a particular Nike and another in a particular adidas without either brand being “wrong.”
It is also unsafe to conclude, “I wear a US men’s 9, so every TTS sneaker must be a US men’s 9.” The printed size is a label within a system. Your foot experiences the actual interior space, and two boxes can show the same number while the shoes feel very different on foot.
Read a TTS recommendation as: “this model tends to work in your reference size”. If you do not yet know that reference for the brand, start by measuring your feet and checking the official chart, rather than guessing from another pair’s size.
Why can two shoes in the same size fit differently?
Fit involves more than length. A shoe can have enough space between the longest toe and the front while still pinching at the sides, pressing on the instep, or allowing the heel to slip. That happens because the feel on foot comes from a combination of shape, proportions, materials, and construction.
Length
This is the distance from the heel to the longest toe and is usually the starting point for size charts. It matters, but does not describe how the whole sneaker wraps around your foot.
Width
Someone with wide feet may feel pressure at the sides in a model most people consider TTS. Someone with narrow feet may feel more room in the same pair. That does not automatically mean the review was wrong; it means “most people” do not have your feet.
Volume and instep height
Two feet with similar lengths and widths can have different volumes. A higher instep takes up more vertical space and can change pressure from the upper, tongue, and lacing system. Replacement insoles and thicker socks also affect the space available inside the shoe.
Toe box and heel
The toe box is the area that accommodates your toes. A roomy toe box can make a shoe feel large even when the length is right; a low or narrow one can make it feel tight. At the back, heel shape, the collar, and lacing influence heel hold. Heel slip, or movement around the heel, may involve size, construction, or lace adjustment.
Last, materials, and construction
The last is the three-dimensional form around which a shoe is built. It helps define width, volume, curvature, and space at the front. In its foot-measuring guide, Nike explains that different models may use different lasts, and that materials, closures, and intended use also affect how a shoe feels.
Structured leather, knit, mesh, suede, lining, and padding occupy space and stretch in different ways. Some materials settle with wear, but that is not a reason to buy an uncomfortably tight pair and expect the material to fix an unsuitable size. To locate the toe box, upper, heel, and other parts mentioned here, see our sneaker anatomy guide.
TTS, size up, and size down: what is the difference?
These expressions exist because your reference size does not always deliver your preferred fit in every model:
- TTS or go TTS: choose your reference size.
- Size up: choose a size larger than your reference.
- Half size up: go up half a size in the stated system, for example from US 9 to US 9.5.
- Size down: choose a size smaller than your reference.
- Half size down: go down half a size in the stated system.
- Runs big: the model tends to fit larger or roomier than the reference.
- Runs small: the model tends to fit smaller or tighter than the reference.
- Snug fit: a close, secure fit, which does not necessarily mean the shoe is too small.
- Roomy fit: a more spacious feel, which may be intentional.
- Wide fit: may indicate a wider last or a specific “Wide” version, depending on the brand and product.
“Half a size up” should not automatically be transferred between US, UK, EU, and Brazilian sizing. A half-step in one system does not necessarily equal a half-step in another, and available sizes vary by brand. Always identify which scale a review uses.
Is US, UK, EU, or BR size conversion the same as TTS?
No. Conversion and fit answer different questions:
- Conversion: which size in one system corresponds to a size in another?
- TTS: how does this model fit relative to my reference size?
A chart can help you find equivalents across US, UK, EU, Brazilian sizes, and centimeters, but cannot tell you on its own whether the toe box is narrow or the upper presses on your instep. For the conversion step, consult Nike’s official size charts for the applicable product category. Then check the exact model’s fit recommendation.
Pay attention to size categories, too. US men’s and US women’s are not the same scale; unisex models may show both; and GS versions may differ from adult versions in sizing, proportions, and construction. The same care applies to EU and CM/JP labels: use the brand’s official chart, rather than an improvised formula.
How do you find your reference size?
Start with your feet, rather than your memory of the last box. Nike’s official procedure includes measuring at the end of the day, wearing the intended type of socks, placing your foot on a firm surface, marking the heel and longest toe, repeating on the other foot, and using the larger foot’s measurement when consulting the chart.
- Wear the socks you plan to use with the shoes.
- Place a sheet of paper on a firm floor and rest your full foot on it.
- Mark the farthest point of the heel and the longest toe.
- Measure the distance in centimeters, or inches if that is what the chart uses.
- Repeat on the other foot and use the larger measurement as your reference.
- Consult the correct chart for the brand, category, and size range.
Do not automatically add a fixed amount of extra room in centimeters. Categories and brands may have their own guidance. The measurement creates a better starting point; the product-specific recommendation completes the decision.
How can you tell whether a model is really TTS?
The most useful source is often the Size & Fit section on the official product page. Supplement it with specific information: the more generic the advice, the less it knows about the shoe you intend to buy.
- Check the model’s official page. Look for size recommendations, size range, Wide versions, and fit notes.
- Confirm the exact edition. Materials, padding, and construction can change between versions of the same silhouette.
- Read reviews with context. Give more weight to reviewers who state their usual size, foot width, tested size, and preferred fit.
- Use community feedback as a supplement. Different opinions may reveal how the model responds differently to wide, narrow, or higher-volume feet.
- Check exchanges and returns. When buying online, a good policy reduces the impact of a recommendation that does not work for your foot.
Avoid automatically applying an adult review to GS, a lifestyle Dunk review to an SB Dunk, or one edition’s recommendation to every collaboration. Even familiar names can hide different constructions.
Is the Air Force 1 TTS?
It should not be presented as a generic example of TTS. In its official Air Force 1 sizing guide, Nike says the model generally runs large because of its roomy toe box. For a snugger fit, the general recommendation is to go half a size below your usual Nike size.
Nike makes an important exception: people with wide feet may prefer their usual Nike size rather than going down half a size. It also cautions that certain editions may fit differently because of upper materials or midsole changes. Even a classic silhouette, then, requires checking the version; materials and construction affect fit, too.
Is the Ultraboost TTS?
It depends on the generation, and adidas offers a good example of why recommendations should be specific. In its official Ultraboost sizing guide, the brand calls the Ultraboost 1.0 TTS for most people but recommends going up half a size for wide feet.
The same guide describes the Ultraboost 5 as true to size and provides separate guidance for other generations. This teaches more than a list of “TTS sneakers”: even within one line, changes to knit, support, and construction make it worth checking the exact generation.
Intended use matters, too. An Ultraboost chosen for running does not have to reproduce exactly the feel someone prefers in a lifestyle sneaker. TTS describes the relationship to size; it does not decide how much room, support, or firmness you want for each activity.
Does TTS work for wide, narrow, or higher-volume feet?
It works as a starting point, rather than an automatic answer. A model considered TTS may pinch a wide foot, feel loose on a narrow one, or press on a high instep. Going up or down a size can change length without fully resolving width or volume.
When Wide or Extra Wide versions exist, compare them with simply going up a size. A wider construction is intended to change the shoe’s geometry; sizing up changes other dimensions as well. For narrow feet, do not adopt an “always size down” rule: lacing, heel shape, volume, and personal preference still matter.
Is TTS the same as comfort?
No. TTS concerns relative sizing; comfort involves much more. Shape, cushioning, support, flexibility, lining, internal seams, socks, insoles, and intended use all affect the experience.
Two people may agree a model is TTS and completely disagree about its comfort. They may also choose different sizes because one prefers a snug fit while the other wants more space. TTS therefore does not guarantee fewer blisters, better performance, or freedom from discomfort.
Some materials may soften with wear, but do not count on that to correct an unsuitable size. Avoid a pair that already creates uncomfortable pressure when you try it on.
Start with your foot measurements, consult the official chart, check the exact edition, and read recommendations in context. For more terms without turning slang into an absolute rule, explore the Sneakerhead Dictionary.