I am new to electronics, and I inherited a breadboard from my grandfather. I could fit 2.54 mm headers into it (as shown below):

Old Breadboard - 40 Pin Header

I recently got a new breadboard, but the holes seem to be closer to each other, and the headers won't fit (shown below, on the left it looks like it lines up, but as it gets further to the right the pins are further and further from the hole):

New Breadboard - 40 Pin Header

I also got a compatible/clone Arduino Nano, which plugs just fine into my new (narrower) breadboard, but not my older (wider) breadboard (pictures below):

Old Breadboard - Compatible Nano New Breadboard - Compatible Nano

I measured the pitch and found that the old breadboard has a 2.54 mm pitch, but the new breadboard seems closer to 2.45 mm.

Is there more than 1 standard for breadboard and header pitch, or if not, what's going on???


  • 1
    \$\begingroup\$ all nominally 0.1" breadboards should be 2.54 mm pitch. However, some cheap ones may be made incorrectly. The new one you have should still work with a short run of pins. You just have to buy better quality. \$\endgroup\$ – Neil_UK Dec 26 '20 at 12:54
  • \$\begingroup\$ I did think it was a quality issue as well UNTIL, to my surprise, my Compatible Nano's headers fit perfectly into this new breadboard! \$\endgroup\$ – ktstuff Dec 26 '20 at 13:43
  • 1
    \$\begingroup\$ Measure the distance over 50 rows or so. \$\endgroup\$ – Chris Stratton Dec 26 '20 at 15:33
  • \$\begingroup\$ It's one of the realities with US based suppliers using inches and the rest of the world using metric. As Chris Stratton says measure the distance over 50 rows. \$\endgroup\$ – StainlessSteelRat Dec 26 '20 at 15:48

2.54mm (or 100mil) spacing is pretty common, but there do exist other variant spacings for breadboards and perfboards (1.27mm, 5.08mm, etc). I believe the Arduino Nano is designed with 2.54mm spacing, but it probably fits on your 2.45mm breadboard since the pins might be flexing on it.

  • \$\begingroup\$ Thank you for your reply. Do these different pitch standards have names? When I order components for my projects, I want to be able to make sure they fit my breadboard. I now have some items that fit my old breadboard and some that fit my new breadboard. It might get messy if I can't standardise. \$\endgroup\$ – ktstuff Dec 26 '20 at 11:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.