Choosing the right frame size is the most important step when buying a second-hand bicycle. A bike that perfectly matches your body height prevents saddle pain, knee complaints, and back pain, and ensures that you cycle in a relaxed manner with maximum control. In this complete guide, we explain step-by-step how you can calculate your ideal frame size in under two minutes using your inseam or body height.
Why is the right frame size so important?
The frame is the foundation of every bicycle. While you can adjust the handlebars and saddle to a certain extent, the geometry of the frame is fixed. A frame that is too small forces you into a hunched position with too much pressure on your wrists and shoulders, while a frame that is too large makes it difficult to reach the ground stably with your feet when stopped at traffic lights.
Method 1: Calculating frame size based on body height
The fastest and most common way to determine your frame size is based on your total body height. Because Dutch and Belgian bicycle manufacturers (such as Gazelle, Batavus, and Sparta) use standard frame sizes, you can use the sizing chart below directly as a reliable guideline:
| Body height (cm) | Frame size (Women) | Frame size (Men) | Wheel size |
|---|---|---|---|
| 150 – 160 cm | 45 – 49 cm (XS/S) | 48 – 51 cm | 28 inch |
| 160 – 172 cm | 49 – 53 cm (M) | 51 – 54 cm | 28 inch |
| 170 – 182 cm | 53 – 57 cm (L) | 54 – 58 cm | 28 inch |
| 180 – 192 cm | 57 – 61 cm (XL) | 58 – 62 cm | 28 inch |
| 190 – 205 cm | 61+ cm (XXL/XXXL) | 62 – 66 cm | 28 inch |
Method 2: The most accurate formula (Inseam)
Do you have relatively long or short legs compared to your torso? Then measuring your inseam is the most precise method. Follow these simple steps:
- Stand barefoot with your heels against a straight wall, with your feet about 15 cm apart.
- Place a book or ruler horizontally between your legs and pull it up slightly into your crotch (as if you were sitting on a saddle).
- Use a measuring tape to measure the distance from the top of the book to the floor. This is your inseam in centimeters.
- The formula: Multiply your inseam by 0.68.
Calculation example: Is your inseam 80 cm? Then the calculation is: 80 x 0.68 = 54.4 cm. Your ideal frame size is then 54 cm or 55 cm.
What if you are between two frame sizes?
If you fall exactly between two sizes, for example at 53.5 cm, look at your preferred riding style:
- Choose the smaller size (53 cm) if you use the bike for short city rides and maneuverability is important to you. A smaller frame steers more directly and feels livelier.
- Choose the larger size (55 cm) if you cycle longer distances daily or prefer a stable, upright riding position.
Additional factor: Suspension seatpost
Does the bike have a suspension seatpost? Keep in mind that a suspension seatpost adds about 3 to 4 centimeters of height on top of the frame. In that case, subtract approximately 3 cm from your calculated frame size to prevent the saddle from being too high even in its lowest position.
How Cheapassbikes helps you with the right size
At Cheapassbikes, we want you to be able to ride away worry-free. That is why you will find a clear height recommendation for every unique refurbished bike in our webshop (e.g., "Ideal for 168-180 cm"). Additionally, our mechanics in the Rotterdam workshop will pre-adjust the handlebars and saddle to your height before free delivery.
If the size doesn't feel 100% right at home? No problem: with our 14-day reflection period and free exchange service, we will always find a model that perfectly suits your body.