Shoe Size Converter Guide: Get the Right Fit When You Buy Shoes Online
Buying shoes online is easy. Making sure they actually fit when they arrive is the hard part. Sizes change between brands, countries and even between men’s, women’s and kids’ styles. That’s where a reliable shoe size converter makes a big difference.
On this page you’ll learn how different shoe size systems work, how to measure your feet at home in a few minutes, and how to use your measurement with this calculator to pick the best size in US, UK, EU and CM. Along the way, we’ll share simple tips that can save you from painful shoes and annoying returns.
1. US, UK, EU and CM – What’s the Difference?
The most common shoe size systems you’ll see online are US, UK, EU and CM (centimeters). They all describe roughly the same range of foot lengths, but use different starting points and numbering rules.
- US sizes are used mainly in North America and have separate scales for men, women and kids.
- UK sizes look similar to US but the numbers are slightly smaller most of the time.
- EU sizes are used across Europe and are written as larger numbers, like 42 or 39.5.
- CM sizes are based on your actual foot length in centimeters and are common in Japan and other parts of Asia.
For example, a typical men’s size might look like this for the same person: US 9 → UK 8.5 → EU 42 → 27 cm. Our calculator does these conversions instantly for men, women and kids.
2. How to Measure Your Foot Length at Home
Foot length in centimeters is the best starting point. It’s quick to measure and works with every brand and country.
- Place a sheet of paper on the floor with one edge touching a wall.
- Stand on the paper with your heel gently against the wall.
- Mark the tip of your longest toe with a pen.
- Measure the distance from the wall edge to the mark in centimeters.
- Repeat for the other foot and use the larger value.
Measure in the afternoon or evening when your feet are slightly larger. Morning measurements are usually a bit smaller and can lead to tight shoes later in the day.
Once you know your CM value, choose the CM (Centimeters) option in the calculator, type the number and the tool will show your approximate US, UK and EU sizes immediately.
3. Typical Conversion Examples
Shoe size charts are not perfectly identical between brands, but the patterns are similar. Here are a few rounded examples to give you a feel for the numbers:
- Men: US 9 ≈ UK 8.5 ≈ EU 42 ≈ 27 cm
- Women: US 8 ≈ UK 6 ≈ EU 38.5 ≈ 25.5 cm
- Kids: US 5 ≈ UK 4.5 ≈ EU 21.5 ≈ 14 cm
If your size falls between two options, most people prefer to size up slightly for closed shoes, especially if they plan to wear thicker socks.
4. Men’s, Women’s and Kids’ Sizing Explained
Shoe sizes are also grouped by gender and age. A women’s US 8 is not the same length as a men’s US 8. Generally:
- Women’s US sizes are about 1.5–2 numbers higher than men’s for the same length.
- Kids’ sizes follow their own chart, and the largest “big kid” sizes overlap with smaller adult sizes.
- Unisex shoes usually use men’s sizing. A woman often needs to subtract about 1.5 from her usual women’s size to find the unisex size.
That’s why the calculator makes you pick Men’s, Women’s or Kids’ before converting – the relationships between the numbers are slightly different for each group.
5. Tips for Buying Shoes Online Without Regretting It
A few simple habits can make online shoe shopping much safer:
- Measure your feet in CM at least once a year and before buying a new brand.
- Use this shoe size converter to find your closest size in the store’s system.
- Check the brand’s own size chart and read a few reviews about how the shoes fit.
- If you are between sizes, lean towards the slightly bigger option for everyday shoes.
- Look at the return and exchange policy before ordering, just in case.
When you are comparing prices, you can also open our loan calculator or mortgage calculator for bigger purchases, or use the BMI calculator if you are tracking fitness along with new running shoes.
The more you shop online, the more valuable a simple tool like this becomes. After a few uses you’ll know your “default” US, UK and EU sizes by heart and can quickly spot when a brand runs unusually large or small. Save this page, and feel free to explore other calculators on CalculatorForYou.online whenever you need fast, reliable answers.
Frequently Asked Questions About Shoe Size Conversion
1. What is the easiest way to convert my shoe size?
The easiest way is to measure your foot in centimeters, select the CM option in the calculator and let the tool show you the closest US, UK and EU sizes. This avoids jumping between different charts and brands.
2. Why are my US and UK shoe sizes different numbers?
The US and UK systems use slightly different starting points. For men, the UK size is usually about 0.5 smaller than the US size. Women’s sizes often have a bigger gap. The converter accounts for these differences automatically.
3. How accurate is this shoe size converter?
The converter uses standard international size relationships and CM charts, which are accurate for most people. However, every brand is a little different, so treat the result as a strong starting point and still check the brand’s own chart when possible.
4. Do I need to change size for sports shoes or running shoes?
Many runners prefer about 0.5–1 size larger than their everyday shoes to allow for swelling and thicker socks. You can use the converter to find your normal size, then go up half a size for performance or long-distance running.
5. How often should I re-measure my feet?
Feet can change over time with age, weight changes or pregnancy. For adults, measuring once every year or two is a good habit. For children, measure every few months, especially during growth spurts.
6. Can I use this tool for sandals and open shoes?
Yes. The size conversion works the same way, but you may feel more comfortable with a slightly snugger fit in open sandals than in closed winter boots. When in doubt, check the brand’s guidance.