It happens at the doctor's office. Or maybe you're filling out a visa application or buying a bike online from a European retailer. You see that number—170—and if you grew up using the imperial system, your brain probably hits a wall. Converting 170 cm is how many inches isn't just a math problem; it's a way to visualize where a person or an object fits into the physical world.
Most people just want the quick answer. Fine. 170 centimeters is roughly 66.93 inches.
If you're rounding up for a dating profile or a casual conversation, that’s 5 feet 7 inches. But there’s a lot more to this specific measurement than a simple calculator output. In the world of ergonomics, fashion, and global health statistics, 170 cm is a massive "sweet spot" for design and human height averages.
The math behind 170 cm is how many inches
We have to look at the math, but I'll keep it painless. The magic number is 2.54. That is the exact number of centimeters in one inch, as defined by the international yard and pound agreement back in 1959.
To get your answer, you take 170 and divide it by 2.54. You get 66.929133... and so on. In most practical scenarios, we just call it 66.93 inches.
Wait.
How does that translate to feet? Since there are 12 inches in a foot, you take that 66.93 and divide by 12. You get 5 feet with 6.93 inches left over. Almost everyone just rounds this to 5'7". It’s a clean number. It’s a relatable height.
But honestly, that missing 0.07 of an inch matters if you're an engineer or a tailor. If you are building a custom car seat or a high-performance carbon fiber bicycle frame, those fractions of a millimeter can be the difference between "fits like a glove" and "my lower back hurts."
Why 170 cm is the "Global Average" anchor
If you look at data from the NCD Risk Factor Collaboration (NCD-RisC), which tracks human height trends globally, 170 cm sits right in the middle of a very interesting demographic curve.
For men, 170 cm is slightly below the average in places like the United States (where the average is about 175 cm) or the Netherlands (where men often tower at 183 cm). However, in many parts of Southeast Asia, Latin America, and Africa, 170 cm is actually considered tall or well above average.
For women, 170 cm is quite tall globally. In the U.S., the average woman is about 162 cm (5'4"). If you're a woman standing at 170 cm, you're essentially at "model height" entry levels. You'll likely find that standard "petite" clothing is way too short, but you aren't quite into the "tall" specialized ranges yet.
The psychology of being 5'7"
There is a weird psychological quirk about being 170 cm. In the metric world, 170 feels like a solid, rounded milestone. In the imperial world, 5'7" often feels "short" to men because of the strange social obsession with the 6-foot mark.
It's a bit ridiculous.
Tom Cruise is famously cited around this height (though some tabloids argue he's closer to 172 cm). Lionel Messi, arguably the greatest soccer player ever, is actually shorter, coming in at 169 cm. When you realize that some of the most influential people on the planet occupy the 170 cm space, the "inches" don't seem to matter as much.
Converting 170 cm for clothing and gear
If you're shopping for clothes and trying to figure out if 170 cm is how many inches for a size chart, you need to be careful. Manufacturers don't all use the same math.
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A "Medium" jacket in Japan is often designed for a 170 cm frame, but it will feel tiny on a 170 cm person from North America. Why? Because it isn't just about the height; it's about the proportions of the torso versus the legs.
- Bikes: If you are 170 cm, you are usually looking at a 52 cm or 54 cm road bike frame. In inches, that’s about a "Small" or "Medium" depending on the brand.
- Snowboards: You’d likely want a board that reaches your chin, which for a 170 cm person is roughly a 150-155 cm board.
- Yoga Mats: A standard yoga mat is 68 inches long. Since 170 cm is 66.9 inches, you’ll fit almost perfectly on a standard mat with about an inch to spare. Lucky you.
Accuracy in medical and scientific settings
In a clinical setting, accuracy is everything. Doctors don't use "5 foot 7" on your chart; they use centimeters. This is because the metric system is decimal-based, making it much harder to make a rounding error when calculating Body Mass Index (BMI) or medication dosages based on body surface area.
If a nurse records you at 170 cm, and a pharmacist calculates a dose based on 67 inches, there is a tiny discrepancy. In most cases, it's irrelevant. But for precision medicine—like certain types of chemotherapy—the metric measurement is the gold standard because it eliminates the confusion of 12-base versus 10-base math.
Common misconceptions about the conversion
People often think they can just multiply by 2.5 and be "close enough." If you do that with 170 cm, you get 68 inches (5'8"). You've just "grown" an inch through bad math.
Don't do that.
Another mistake is forgetting that height changes throughout the day. You are tallest in the morning because your spinal discs are hydrated and expanded. By the time you go to bed, gravity has compressed those discs, and you might actually measure 168.5 cm instead of 170 cm. If you're obsessing over whether you're exactly 66.9 inches, just remember that your height is a moving target anyway.
Practical steps for using this measurement
If you need to use this measurement for something official, here is exactly how to handle it.
First, check the requirements. If it's a government form for the U.S. or UK, they usually want feet and inches. Write down 5'7". If you are filling out a medical form or a fitness profile for an app like Strava or MyFitnessPal, try to keep it in centimeters if the app allows it. It’s simply more precise.
Second, if you're buying furniture or a standing desk, don't just look at your height. Look at your "seated height." A person who is 170 cm might have long legs and a short torso, or vice versa. This changes where your elbows hit the desk.
Third, when buying international clothes, always look at the "model is wearing" section. If the model is 185 cm and wearing a large, and you are 170 cm, you should probably size down to a small or medium.
Finally, stop worrying about the 6-foot "requirement" that social media likes to push. 170 cm is a functional, agile, and extremely common height that the entire world is literally built to accommodate. From doorways to airplane seats, the world is your oyster at 170 cm.
For those who need the absolute precision one last time: 170 cm is 66.929 inches. Round to 67 if you're feeling generous, or 5'7" if you're being practical.
Actionable Insight: To get the most accurate fit for clothing or equipment, measure your wingspan (reach) and inseam in centimeters alongside your height. Comparing these to a manufacturer's size chart is far more effective than just converting your total height into inches.