Standing over the frame
There should be about 5–8 cm of clearance over the top tube on city and trekking bikes, a bit more on mountain bikes.
Size guide by Karaarslan Bike
What bike size do I need? calculator & chart.
The right frame size depends on your height and inside-leg length — and on the type of bike. Here is our chart, a calculator and practical tips. In the end, the test ride decides: at our shop in Lünen, no appointment needed.
- Inside-leg calculator
- Chart for every bike type
- Test ride, no appointment
- Personal advice
Calculate your bike size
Enter your height. Adding your inside-leg length makes the result more accurate.
Recommended frame size
Please enter your height (120–220 cm).
Guide values — sizes vary by manufacturer and geometry. A test ride gives certainty.
Chart: bike size by height
Frame size is given in centimetres for city and trekking bikes, and usually in inches for mountain bikes.
| Height | City / trekking / e-bike | Mountain bike | Road bike |
|---|---|---|---|
| 150–160 cm | 41–46 cm | 13–14″ (XS) | 47–50 cm |
| 160–170 cm | 46–50 cm | 15–16″ (S) | 50–53 cm |
| 170–180 cm | 50–55 cm | 17–18″ (M) | 53–56 cm |
| 180–190 cm | 55–60 cm | 19–20″ (L) | 56–59 cm |
| 190–200 cm | 60–64 cm | 21–22″ (XL) | 59–62 cm |
| > 200 cm | > 64 cm | ≥ 23″ (XXL) | > 62 cm |
Between two sizes? Sporty riding → smaller frame, relaxed and upright → larger frame.
How to measure your inside leg
Inside-leg length is more precise than height. Here is how:
- Take off your shoes and stand straight with your back against a wall, feet about 15 cm apart.
- Slide a book horizontally between your legs and press it gently upwards.
- Measure from the top edge of the book to the floor — that is your inside leg.
- Formula: city/trekking = inside leg × 0.66 · mountain bike (inches) = inside leg × 0.226 · road bike = inside leg × 0.665.
How to tell a frame fits
Knee while pedalling
With the pedal at its lowest point your leg is almost straight — the knee stays slightly bent.
Handlebars & back
You reach the handlebars comfortably without locking your arms or rounding your back.
Step-through frames
Here the seating position matters most — getting on is easy for every size.
E-bikes
Same values as trekking bikes. Because of the extra weight a test ride is especially worthwhile.
Buying used
Used-bike ads often omit the frame size — we measure every bike for you.
Used bikes →Questions about bike size
Message us on WhatsAppWhat frame size do I need at 170 cm?
At around 170 cm a city or trekking bike with a 48–52 cm frame, a 16–17 inch mountain bike or a 52–54 cm road bike usually fits. Your inside leg makes it more precise.
What bike size at 180 cm?
At around 180 cm the frame size is usually 53–57 cm (city/trekking), 18–19 inches (mountain bike) or 55–57 cm (road bike).
How do I calculate frame size from inside leg?
City and trekking: inside leg × 0.66. Mountain bike in inches: inside leg × 0.226. Road bike: inside leg × 0.665.
What if I am between two sizes?
Sporty riders tend to choose the smaller frame; if you prefer an upright, relaxed position, take the larger one. Best of all, try both sizes with us.
Does the chart also apply to e-bikes?
Yes, e-bikes use the same values as city and trekking bikes.
Can I test ride bikes in my size?
Yes. At Karaarslan Bike, Alstedder Straße 5 in Lünen, you can test ride any bike without an appointment.
Test ride in your size.
Over 100 bikes in many frame sizes — come by and find the bike that really fits.
Karaarslan Bike · Alstedder Straße 5 · 44534 Lünen · +49 163 7390 301