When searching for a new pair of shoes, many people focus only on length and width, overlooking a third significant factor: the time of day. Foot size is not static; it changes throughout the day due to physiological factors. This daily fluctuation means that a shoe that feels comfortable in the morning may feel painfully tight by evening. Timing your fitting accordingly is the most effective way to ensure a comfortable and lasting fit for your new footwear.
The Science of Foot Swelling
The primary reason for daily foot size fluctuation is the temporary accumulation of fluid in the lower extremities, a phenomenon often referred to as dependent edema. Throughout the day, the constant pull of gravity draws blood and other bodily fluids downward toward the feet and ankles as a person stands or sits upright. This fluid retention causes the feet to expand slightly in volume and dimension, which can sometimes amount to a change of a half-size in footwear.
Activity level also contributes to this daily swelling, as increased blood flow to the feet during walking or exercise can lead to temporary tissue expansion. Warm temperatures further exacerbate the issue because heat causes blood vessels to dilate, increasing blood flow to the skin and surrounding tissues. Since these factors are cumulative, the foot’s maximum size is reached after many hours of activity.
Identifying the Optimal Time for Fitting
The best time to try on new shoes is during the late afternoon or early evening, generally after 3:00 p.m. By this point, the feet have usually experienced a full day of standing and walking, ensuring they are at their largest and most swollen state. Fitting shoes at this maximum size guarantees that the footwear will accommodate the foot when it is most expanded, preventing uncomfortable tightness later in the day.
If shoes are purchased earlier, such as first thing in the morning, the foot will be at its smallest size, and the new pair will likely feel snug or even painful later on. This mistake leads to blisters, pressure points, and discomfort, as the unyielding shoe material cannot accommodate the natural afternoon expansion. By adjusting your shopping trip to this window, you select a size that remains comfortable from morning until night.
Essential Shoe Fitting Techniques
Even with the correct timing, proper technique during the fitting process is necessary to ensure an optimal shoe purchase. You should always have both feet measured, as one foot is often slightly larger than the other. The final shoe size must be based on the dimensions of the larger foot.
Measuring and Weight Bearing
It is important to stand up while trying on shoes, as the foot naturally lengthens and widens under the body’s weight. You must also wear the specific type of sock or hosiery you intend to use with the new shoes during the fitting.
Checking the Fit
The shoe should provide a thumb’s width of space—approximately half an inch—between the end of the longest toe and the tip of the shoe. This space allows for natural toe movement during walking. The heel should feel snug to prevent slippage, and the ball of the foot should fit comfortably in the shoe’s widest part. Finally, take a short walk around the store to confirm there is no pinching, rubbing, or excessive heel movement.