Is it possible to measure your sit bones at home?

You can do it on any surface which will conform to the shape of your butt, like a piece of memory foam.

Sit on it, with your knees higher than your seat by 4-6 inches, then measure the center of the depressions left.

There are different types of memory foam, and some will have a more durable impression than others.

A fresh piece of corrugated cardboard on a hard surface such as a coffee table. Sit down and try to mimic the upper body position you have on your bike. Your sit bones change position based on how your pelvis is tilted. Your sit bones should crush the corrugated cardboard slightly and leave two indentations. Measure center to center as best you can.

I've used this method which worked well:

1. Fill a large size ziploc bag with icing sugar. Icing sugar's fine texture means that it binds together when compressed. This is what we want - it will hold the shape of your buttprint after you get up.

2. Close the bag making sure to squeeze out the air.

3. Place on hard chair.

4. Sit while assuming the degree of forward rotation that you intend to cycle with. The distance between your sit bones change depending on this rotation.

5. Get up cleanly and measure the distance between the depressions.

Here's a link to a video that may help you:

In this technique all you need is a piece of corrugated cardboard and some chalk.

None of the above techniques worked for me. I made no impression on the corrugated cardboard and the foil just showed a nice big bum-print after sitting a few different surfaces. I came up with my own technique that's a bit more trial and error but seemed to work for me.

I got two small erasers, put them on a chair, sat on them and moved them around until they felt like I was sitting on my sit bones. Then I got up and measured how far apart they were.

There is one more method people here aren't talking about... Sit on a bike on a trainer, get into riding position, and have someone you don't mind touching you physically measure your sit bones, in proper riding position. You can feel someone's sit bones on their butt. They're pretty obvious once you're touching them.

I know this is an old thread but it's the top one on Google and I found it helpful. I tried all the methods above and I didn't have a lot of luck so I wanted to share what I tried.

I made some playdough using the first no cook recipe I found on Google (it was fun and doesn't take long). I then put it between two pieces of cling film and pressed it to about 2" thick, placed it on a hard surface (my kitchen floor) and put a tea towel over it so my legs didn't stick to the cling film. I then sat on it with my back in roughly my riding position. The impression of my sit bones is really clear, I can see 2 circles (see image) and I measured the distance between the centres. I tried a few times and it was consistent.

Find a manageable hard flat surface

1 sheet fairly damp kitchen roll paper
2 sheets of dry kitchen roll paper on top

Sit down on paper and lean forward to 45 deg

Very slight wiggle your arris

Stand up

Measure centre of indents

Mine = 110mm

Therefore 145 saddle size.