Does your bike saddle hurt, go numb, and leave you aching after every ride? In most cases the saddle itself isn't the problem – it's that the saddle width doesn't match your body. The deciding value: your sit-bone width. If you know it, you buy the right saddle. If you don't, you're guessing – and losing.
Here you'll learn how to measure your sit-bone width at home in five minutes, how to work out the right saddle size, and which saddle width fits your result.
Why sit-bone width matters so much
Your pelvis has two bony protrusions at the very bottom – the so-called sit bones (medically: ischial tuberosities). When you sit on a chair, you feel them as hard points under your backside. These two bones are exactly what should rest on the bike saddle and carry your weight.
The problem: the distance between the sit bones is different for everyone. In men it is typically between 10 and 14 cm, in women often between 11 and 16 cm. A saddle that works perfectly for your neighbour can be a source of pain for you – because their sit bones simply sit differently from yours.
If the saddle is too narrow, your sit bones don't land on the seat surface but beside it. Your entire body weight then presses on the soft tissue in the perineal area – on nerves, blood vessels and sensitive structures. The result: numbness, tingling and pressure pain that get worse with every minute.
If the saddle is too wide, the insides of your thighs chafe against the saddle edges with every pedal stroke. You notice this especially on longer rides – and it doesn't get better over time, it gets worse.
The connection is simple: your sit-bone width determines how wide your saddle needs to be. Your riding position determines how much you add to that value. Even so, most people buy their saddle based on looks, price or "it looks comfortable" – without ever having their saddle measured or measuring themselves.
Measuring sit-bone width – 3 methods
You don't need special tools or an appointment. The first method works with material you probably have at home.
Method 1: Corrugated cardboard (main method, 5 minutes)
This is the most common method and is perfectly sufficient for most people to measure their sit-bone width.
What you need: A piece of corrugated cardboard (approx. 30 × 30 cm, for example from a box), a hard chair or bench, a ruler or tape measure and a pen.
How to do it:
- Place the cardboard with the corrugated side up on a hard, level surface – a wooden bench, a wooden chair or a stair step. No sofa, no upholstered chair. Wear thin trousers without thick seams on the seat, because every seam distorts the imprint by several millimetres.
- Sit down on the cardboard with your full weight. Feet flat on the floor, knees at a right angle, back straight and upright. No hunched back, no hollow back – both tilt the pelvis and shift the sit bones relative to each other.
- Stay seated still for 30 seconds and don't wiggle back and forth. Pull yourself down onto the seat with your hands or lift your feet briefly – this puts your full weight on the sit bones.
- Stand up slowly and look at the cardboard. You will see two distinct impressions – those are your sit bones. In some people they are clearly visible round dents, in others more oval depressions.
- Mark the centre of each impression with a pen and measure the distance between the two points – not between the edges. That is your sit-bone width.
Tip: If the impressions aren't distinct enough, put a second piece of cardboard under the first and sit down more firmly. If the imprints stay unclear, use method 2 with aluminium foil.
To be safe, measure twice and take the average. For most people the sit-bone width is between 9 and 16 cm.
Method 2: Aluminium foil (if the impressions stay unclear)
The principle is identical – but aluminium foil shows the impressions more clearly than corrugated cardboard. This method is especially suitable if you can't make out clear impressions with the cardboard method.
How to do it:
- Fold a piece of aluminium foil twice so that it is four layers thick (approx. 30 × 30 cm).
- Place the foil on a hard surface – ideally on a wooden board or a stair step.
- Sit on it exactly as in the cardboard method: upright, feet flat on the floor, knees at a right angle, sitting still for 30 seconds.
- The foil deforms permanently. You see two clear hollows whose centres you can simply measure.
The advantage: aluminium foil is unforgiving – every pressure point stays visible. This makes the centres easier to read if the cardboard doesn't give a clear picture. The measured value itself stays the same.
Method 3: Have it measured at a bike shop
Many bike shops offer professional sit-bone measurement. You sit on a special pressure-sensing mat or a gel cushion that digitally records the exact distance and the pressure distribution.
When is it worth it?
- If you still have discomfort despite measuring yourself and having a suitable saddle.
- If you ride road or mountain bikes ambitiously and every millimetre counts.
- If you're having a complete bike-fitting analysis done – saddle measurement is usually included there.
For the vast majority of cyclists, the home methods are entirely sufficient. The corrugated-cardboard method delivers results with an accuracy of about ± 5 mm – and that's enough to determine the saddle width and the right size.
Bike saddle size chart – reading your result correctly
Have you measured your sit-bone width? Then you can now read from the table which saddle width suits you. Note: the recommended saddle width is always slightly larger than your sit-bone width, because your sit bones shouldn't rest right at the edge of the saddle but in the middle of the seat surface.
| Sit-bone width (cm) | Recommended saddle width (mm) | Upright riding position | Sporty riding position | Recommended model |
|---|---|---|---|---|
| 9–10 cm | 130–140 mm | 140 mm | 130 mm | Alpensattel 3.0 Race+ |
| 11–12 cm | 143–155 mm | 155 mm | 143 mm | Alpensattel 3.0 Sport+ |
| 13–14 cm | 155–165 mm | 165 mm | 155 mm | Alpensattel 3.0 Komfort+ or Sport+ |
| 15+ cm | 165+ mm | 170+ mm | 165 mm | Alpensattel 3.0 Komfort+ |
Note: Women anatomically have a wider pelvis than men – on average a woman's sit-bone width is 1 to 3 cm greater. That is why women more often choose wider saddles. If you're a woman looking for a suitable saddle, take a look at our bike saddles for women. For men, you'll find the suitable models in our bike saddles for men collection.
Our bike saddles at a glance cover sit-bone widths from 9 to over 15 cm – so you'll find the right width for every measurement.
Sit-bone width in centimetres – which saddle width fits?
The most common question after measuring is about the concrete value. Here is the answer for each measurement individually.
Sit-bone width 10 cm – which saddle width?
For a sit-bone width of 10 cm, a saddle width of 130 to 140 mm fits. In a sporty, forward-leaning position 130 mm is enough, because the pelvis tilts forward and the sit bones rest closer together. If you sit upright, take 140 mm. Suitable model: Alpensattel 3.0 Race+.
Sit-bone width 11 cm – which saddle width?
For a sit-bone width of 11 cm, the suitable saddle width is between 143 and 155 mm. Upright on a city bike or e-bike, 155 mm is right; leaning sportily forward, 143 mm. Suitable model: Alpensattel 3.0 Sport+.
Sit-bone width 12 cm – which saddle width?
12 cm is the most common sit-bone width in men. A saddle width of 143 to 155 mm is suitable – 155 mm in an upright position, 143 mm in a sporty one. Suitable model: Alpensattel 3.0 Sport+.
Sit-bone width 13 cm – which saddle width?
For a sit-bone width of 13 cm you need a saddle width of 155 to 165 mm. Sitting upright, 165 mm is right; sporty, 155 mm. Suitable models: Alpensattel 3.0 Komfort+ or Sport+.
Sit-bone width 14 cm – which saddle width?
A sit-bone width of 14 cm calls for a saddle width of 155 to 165 mm. This value is more common in women than in men, because the pelvis is built wider. Upright 165 mm, sporty 155 mm. Suitable model: Alpensattel 3.0 Komfort+.
Sit-bone width 15 cm and more – which saddle width?
From a sit-bone width of 15 cm you need a saddle width of at least 165 mm, when sitting upright rather 170 mm. A saddle that is too narrow presses directly on soft tissue instead of bone here – the most common cause of numbness. You'll find wider models in the Women's Bike Saddle Test 2026.
The measured width is only half the battle: a suitable saddle at the wrong height or tilt hurts just the same. How to adjust both is explained in How to adjust your bike saddle correctly.
