The NMRA RP-20.1 Car Weight formula:

Scale | Ratio | Base Weight (oz) | Additional weight (oz) per inch of car body length |
---|---|---|---|

O | 1:48 | 5 | 1 |

On3 | 1:48 | 1.5 | 0.75 |

S | 1:64 | 2 | 0.5 |

Sn3 | 1:64 | 1 | 0.5 |

HO | 1:87 | 1 | 0.5 |

HOn3 | 1:87 | 0.75 | 0.375 |

TT | 1:120 | 0.75 | 0.375 |

N | 1:160 | 0.5 | 0.15 |

This calculator will help you calculate the correct weight for your car.

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Scale | |

Car length | in () |

Recommended Weight | () |

The AMRA Carriage Mass Standard formula:

Scale | Ratio | Passenger (g/mm) | Freight (g/mm) |
---|---|---|---|

F…G | 1:19 … 1:24 |
1.50 | 2.00 |

1-Gauge | 1:32 | 1.10 | 1.50 |

O | 1:43.5 … 1:48 |
0.80 | 1.10 |

S | 1:64 | 0.55 | 0.75 |

OO HO |
1:76 1:87 |
0.40 | 0.55 |

3mm TT |
1:100 1:120 |
0.30 | 0.40 |

N | 1:148 1:160 |
0.22 | 0.30 |

Z | 1:220 | 0.16 | 0.22 |

This calculator will help you calculate the correct weight for your car.

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Scale | |

Car length | in () |

Recommended Weight Freight | () |

Recommended Weight Passenger | () |

The Normes Européennes de Modélisme NEM-302 formula:

Scale | Ratio | Weight (g/mm) |
---|---|---|

II / F / G | 1:22.5 | 4.00 |

1-Gauge | 1:32 | 2.00 |

O | 1:48 | 1.00 |

S | 1:64 | 0.60 |

HO | 1:87 | 0.40 |

TT | 1:120 | 0.25 |

N | 1:160 | 0.17 |

Z | 1:220 | 0.12 |

This calculator will help you calculate the correct weight for your car.

Units | |
---|---|

Scale | |

Car length | in () |

Recommended Weight | () |