Connector pitch converter — mm, inch & mil

Convert connector pin pitch between millimetres, inches and mils — the quick check when matching a header to its mating connector or cable.

Convert pitch

Pitch value

Enter the pitch you know — results update as you type

Unit

1 inch = 25.4 mm, 1 mil = 0.001 inch

Millimetres: 2.54mm
Inches: 0.1in
Mils: 100mil
Micrometres: 2,540µm

Common pitches

Standard connector pitches, shown both ways.

Imperial	Metric	Typical use
0.050"	1.27 mm	SMT board-to-board
0.100"	2.54 mm	through-hole headers
0.156"	3.96 mm	fine / power pitch
0.200"	5.08 mm	fine / power pitch
0.0394"	1.00 mm	fine / power pitch
0.05"	1.27 mm	SMT board-to-board
0.0787"	2.00 mm	fine / power pitch
0.1"	2.54 mm	through-hole headers

0.100″ (2.54 mm) is the most common through-hole header pitch; 0.050″ (1.27 mm) dominates SMT board-to-board connectors.

Related parts

Browse related parts:

pin headers board-to-board connectors ribbon cable

Frequently asked questions

What is the most common connector pitch?

0.100 inch (2.54 mm) is the dominant through-hole header pitch, and 0.050 inch (1.27 mm) dominates SMT board-to-board connectors. Other standard pitches include 0.156 inch (3.96 mm), 0.200 inch (5.08 mm), 1.00 mm and 2.00 mm.

How do you convert connector pitch from inches to mm?

Pitch converts with the fixed relationship 1 inch = 25.4 mm, so 0.100 inch = 2.54 mm and 1 mil (0.001 inch) = 0.0254 mm. The converter takes a pitch in mm, inches or mils and returns the same spacing in all four units, including micrometres.

Does connector pitch have to match between header and socket?

Yes. Pitch is the centre-to-centre distance between adjacent contacts, and pins are spaced equally on both the header and its mating socket — the pitches must be identical or the pair cannot mate. Confusing metric and imperial pitches in a datasheet is a common sourcing error, so confirm the unit before ordering.

How it works

IC Source Direct converts pitch with the fixed inch–millimetre relationship: 1 inch = 25.4 mm and 1 mil = 0.001 inch = 0.0254 mm. Enter a pitch in any unit and the calculator returns the same spacing in mm, inches, mils and micrometres. Pitch is the centre-to-centre distance between adjacent contacts — it has to match across a mating pair, since pins are spaced equally on both the header and its socket.

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IC Source Direct provides this tool for reference only.

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