Buying shoes online is convenient, but choosing the wrong size can quickly turn a good purchase into a return.
The safest approach is not to guess based on the size you normally wear. Instead, measure your feet and compare those measurements with the size chart provided by the brand you are buying from.
To measure shoe size at home, stand on a hard, flat surface, measure from the back of your heel to the tip of your longest toe, repeat the process for both feet, and use the larger measurement when checking the retailer’s UK size guide. Measuring width can also help if you regularly find shoes too tight or too loose.
Clarks recommends measuring both feet and recording the larger measurement, while Nike UK also advises measuring each foot and using the longer measurement when choosing a size.
What You Need to Measure Your Feet
You only need a few simple items:
- A sheet of paper
- A pen or pencil
- A ruler or tape measure
- A hard, level floor
- The socks you expect to wear with the shoes
Avoid measuring on thick carpet because your foot can sink into the surface and make the result less accurate.
If you are buying trainers, work shoes or boots that you will normally wear with socks, wear similar socks while measuring.
How to Measure Shoe Size Step by Step
1. Place the Paper on a Hard Floor
Put a piece of paper on a hard, flat surface.
Make sure it cannot slide while you are standing on it. You can use a small amount of tape if necessary.
Stand naturally rather than measuring while sitting down.
Nike UK’s current footwear measuring guidance tells customers to stand with their weight evenly balanced while taking the measurement.
2. Position Your Heel Correctly
Stand with your foot flat on the paper.
You can place your heel gently against a straight wall or other vertical edge to help identify the back of the heel.
Do not push your foot hard against the wall.
Your aim is to measure its natural length.
3. Mark the Heel and Longest Toe
Mark the back of your heel and the end of your longest toe.
Do not automatically assume your big toe is the longest.
For some people, another toe extends slightly farther.
Clarks specifically advises measuring from the heel to the tip of the longest toe.
4. Measure the Foot Length
Step off the paper.
Use a ruler or tape measure to measure the straight distance between the heel mark and longest-toe mark.
Measuring in millimetres can make comparison with detailed shoe size charts easier.
For example, you might record:
Left foot: 254 mm
Do not immediately convert this into a UK size using a random chart online.
Keep the actual measurement first.
5. Repeat for the Other Foot
Now measure your other foot in exactly the same way.
It is common for two feet not to measure exactly the same.
For example:
Left foot: 254 mm
Right foot: 258 mm
In this situation, use 258 mm when checking the shoe manufacturer’s size guide.
Both Clarks and Nike advise using the larger or longer foot measurement.
How to Measure Foot Width
Length is only part of shoe fit.
Two people can have the same foot length but need different widths.
To measure width, identify the widest part of the forefoot, usually around the ball of the foot.
You can either measure across a tracing or, where instructed by a particular brand, measure around the widest part of the foot.
Clarks’ UK children’s measuring method uses both length and width, and its guidance recommends recording the largest measurements when the two feet differ.
Width systems vary considerably between manufacturers, so use your width measurement with the specific retailer’s chart rather than assuming labels such as “wide” mean exactly the same thing everywhere.
When Is the Best Time to Measure Your Feet?
A useful time to measure is later in the day.
Feet can become slightly larger after you have been standing and walking for several hours.
Clarks recommends measuring towards the end of the day and standing while measuring.
This can be particularly useful when buying footwear you expect to wear for long periods.
For the most realistic measurement, also wear the type of socks you intend to use with the shoes.
Thicker walking or winter socks can affect how boots fit compared with thin everyday socks.
How Do You Turn Foot Length Into a UK Shoe Size?
Once you know the length of your larger foot, open the size chart for the brand and shoe you are considering.
Look for a measurement labelled something such as:
- Foot length
- Heel-to-toe length
- CM
- MM
- UK size
Find the measurement closest to yours and follow the manufacturer’s sizing recommendation.
This step matters because there is no reason to assume that every shoe labelled with the same UK number will fit identically.
Different brands, shoe shapes and styles can feel different even when the number printed inside the shoe is the same.
Nike UK, for example, provides its own foot-length chart and recommends sizing up when a measurement falls between two of its listed sizes. That recommendation applies to Nike’s chart rather than automatically to every footwear brand.
That is why a brand-specific size chart is more useful than a single universal conversion table.
Should You Add Extra Space to Your Foot Measurement?
Do not automatically add an extra centimetre or another arbitrary allowance before choosing a size.
Most reputable manufacturer size charts are designed to help convert foot measurements into an appropriate shoe size.
If you manually add extra length and then use a chart that already accounts for fit, you may end up choosing shoes that are too large.
Measure your actual foot first.
Then follow the instructions supplied by the brand.
If the retailer specifically tells you to add an allowance, follow that guidance.
How to Measure Children’s Shoe Size
Children’s footwear deserves particular care because their feet are still growing.
The basic home method is similar:
- Have the child stand naturally.
- Measure the heel to the longest toe.
- Measure both feet.
- Check width where relevant.
- Use the larger measurements.
- Compare them with the manufacturer’s children’s size guide.
Clarks UK offers dedicated children’s measuring tools and says a professional in-store fitting or its foot gauge provides greater precision than an ordinary tape measure.
Parents should also avoid buying excessively large shoes simply so a child can “grow into them”.
The correct amount of growing room should be determined by the shoe manufacturer’s fitting system or a trained fitter rather than guesswork.
How to Measure for Trainers
The basic measuring process remains the same.
Measure both feet while standing, use the larger measurement, and compare it with the trainer manufacturer’s chart.
If you plan to wear sports socks, wear them while measuring.
Running and training shoes may also have different fit characteristics from casual shoes, so do not assume your normal formal shoe size will automatically be perfect.
Once you have the correct pair, our guide to how to clean white trainers explains how to care for leather, canvas, mesh and other common trainer materials.
How to Measure for Boots
Measure your feet using the same heel-to-toe method, but wear the socks you expect to use with the boots.
This is particularly important for:
- Walking boots
- Hiking footwear
- Winter boots
- Work boots
Thicker socks require more internal space than very thin socks.
Boot fit can also depend on width, instep height and the shape of the upper, so your foot length should be treated as the starting point rather than the only factor.
How to Check Whether New Shoes Actually Fit
Your measurements help you choose a starting size, but the final fit still matters.
When trying shoes on, check that:
- Your toes are not painfully compressed
- Your heel is reasonably secure
- The sides do not pinch
- Your foot does not slide excessively
- The shoe feels secure when walking
- There are no obvious pressure points
Try both shoes, not only one.
Walk around indoors on a clean surface before deciding whether to keep an online purchase.
If one foot is slightly larger, concentrate on making sure the larger foot is comfortable.
Common Shoe Measuring Mistakes
Measuring Only One Foot
Your feet may differ slightly in length or width.
Measure both and use the larger result.
Measuring While Sitting
Standing places your normal body weight through the feet and gives a more realistic measurement.
Measuring on Carpet
Use a hard floor so the paper and your foot stay stable.
Assuming the Big Toe Is Always Longest
Measure to whichever toe reaches furthest forward.
Using Your Old Shoe Size Without Checking
Feet and shoe designs can change over time.
A measurement gives you a better starting point than relying entirely on the size of an old pair.
Using One Size Chart for Every Brand
A conversion found on one footwear website should not automatically be applied to another brand.
Always check the chart belonging to the shoes you intend to buy.
UK, EU and US Shoe Sizes
Online footwear shops often show several sizing systems.
A product may be listed in:
- UK sizes
- EU sizes
- US men’s sizes
- US women’s sizes
These systems do not use identical numbers.
If you need to convert sizes, use the conversion chart supplied by the manufacturer or retailer.
Do not assume that a conversion found on an unrelated website will perfectly match another company’s footwear.
This becomes particularly important when ordering imported shoes online.
You can explore more footwear and style content in the 2DayTimes Fashion section.
Frequently Asked Questions
How do I measure my shoe size at home?
Stand on paper placed on a hard floor, mark the back of your heel and the end of your longest toe, then measure the distance between the marks. Repeat for both feet and use the larger measurement with the manufacturer’s size chart.
Should I measure my feet in centimetres or millimetres?
Either can work, but millimetres provide a precise measurement and are commonly used in detailed footwear size guides.
Which foot should I use if they are different sizes?
Use the larger foot when selecting your starting shoe size.
Should I size up if I am between sizes?
Follow the specific brand’s advice. Nike UK, for example, recommends sizing up when a foot measurement falls between sizes on its own footwear chart. Other brands may provide different guidance.
How do I measure shoe width?
Measure the widest part of your foot and compare the result with the brand’s width guide. Width labelling varies between manufacturers.
Can I use my normal shoe size when buying online?
You can use it as a starting point, but measuring your feet and checking the retailer’s current chart gives you more information before ordering.
Should I measure my feet with socks on?
Yes, if you expect to wear socks with the shoes. Use socks similar in thickness to those you will normally wear.
Final Thoughts
Learning how to measure shoe size at home takes only a few minutes and can make online shoe shopping much easier.
Measure while standing on a hard surface, record the heel-to-longest-toe distance, check both feet and use the larger measurement.
Where useful, measure width as well.
The most important final step is to compare your measurement with the specific brand’s size guide, rather than treating one UK shoe size chart as universal.
A careful measurement cannot guarantee that every style will fit perfectly, but it gives you a much stronger starting point than guessing from an old pair of shoes.
For more practical UK guides, visit 2DayTimes.
