Standard PCB Sizes

Problem Statement

As a PCB designer, it is difficult to pick a "standard" size for designing hardware, where it will be possible to find off the shelf cases or accessories that will fit that board.


Invent a new standard!

Reference Material/Background

  • IEC-602970-3 - Eurocard standard
    • I'm stealing the base card size
    • Based around a 100x160mm card
    • Typically used for test equipment
    • Also influnced Eurorack hardware
  • ISO 216 - Standard Paper Sizes
    • I'm stealing the idea of "half sizes"
    • Every card is 1/2 the larger dimension of the next size up
    • ISO 216 keeps the same ratio - I don't.
  • Sick of Beige v1 - OSHW Board Sizes
    • Really similar approach
    • Based on the "golden ratio"
    • Also has an "alt" square format
    • Steal same spacing for mounting screws/edge keepout

Standard rules

  1. Start with a "base size" of 200x160mm
  2. For each step, reduce the longest dimension by 1/2
  3. For each size, there are four variants:
    1. AR: Full rectangle, corner mounted holes
    2. BR: Full rectangle, "plus" mounted holes
    3. AS: "Slim" rectangle, corner mounted holes
    4. BS: "Slim" rectangle, "plus" mounted holes
  4. For all boards, mounting holes are M3 screws
    • 4x4mm from each corner
    • 3.2mm holes
    • TODO: What about small boards?
    • 6mm keepout around holes (diameter?)
    • 1.7mm edge keepout for case clearance


  • "Plus" mounted holes are for cases that have physical posts in the corners where the PCB must "keep out"

Full case size listing

FamilyVariantFull NameHole Location?Board ShapeWidthLengthcm^2
P0ARP0ARCorner HolesRegular200160320
P0ASP0ASCorner HolesSlim20080160
P0BRP0BRPlus HolesRegular200160320
P0BSP0BSPlus HolesSlim20080160
P1ARP1ARCorner HolesRegular160100160
P1ASP1ASCorner HolesSlim1605080
P1BRP1BRPlus HolesRegular160100160
P1BSP1BSPlus HolesSlim1605080
P2ARP2ARCorner HolesRegular1008080
P2ASP2ASCorner HolesSlim1004040
P2BRP2BRPlus HolesRegular1008080
P2BSP2BSPlus HolesSlim1004040
P3ARP3ARCorner HolesRegular805040
P3ASP3ASCorner HolesSlim802520
P3BRP3BRPlus HolesRegular805040
P3BSP3BSPlus HolesSlim802520
P4ARP4ARCorner HolesRegular504020
P4ASP4ASCorner HolesSlim502010
P4BRP4BRPlus HolesRegular504020
P4BSP4BSPlus HolesSlim502010
P5ARP5ARCorner HolesRegular402510
P5ASP5ASCorner HolesSlim4012.55
P5BRP5BRPlus HolesRegular402510
P5BSP5BSPlus HolesSlim4012.55
P6ARP6ARCorner HolesRegular25205
P6ASP6ASCorner HolesSlim25102.5
P6BRP6BRPlus HolesRegular25205
P6BSP6BSPlus HolesSlim25102.5
P7ARP7ARCorner HolesRegular2012.52.5
P7ASP7ASCorner HolesSlim206.251.25
P7BRP7BRPlus HolesRegular2012.52.5
P7BSP7BSPlus HolesSlim206.251.25