Find the inner and outer diameter dimensions of standard imperial and metric pipes. Use our pipe volume calculator to find the volume and weight each of these sizes can hold.

Inner and outer diameters of common pipe sizes

Inner Diameter |
Outer Diameter |

1/8″ |
0.405″ |

1/4″ |
0.540″ |

3/8″ |
0.675″ |

1/2″ |
0.840″ |

3/4″ |
1.050″ |

1″ |
1.315″ |

1 1/4″ |
1.660″ |

1 1/2″ |
1.900″ |

2″ |
2.375″ |

2 1/2″ |
2.875″ |

3″ |
3.500″ |

4″ |
4.500″ |

5″ |
5.563″ |

6″ |
6.625″ |

Inner and outer diameters of common metric pipe sizes

Inner Diameter |
Outer Diameter |

6 mm |
10.2 mm |

8 mm |
13.5 mm |

10 mm |
17.2 mm |

15 mm |
21.3 mm |

20 mm |
26.9 mm |

25 mm |
33.7 mm |

32 mm |
42.4 mm |

40 mm |
48.3 mm |

50 mm |
60.3 mm |

65 mm |
76.1 mm |

80 mm |
88.9 mm |

100 mm |
114.3 mm |

125 mm |
139.7 mm |

150 mm |
165.1 mm |