INPUTS
HO is the default. Others adjust the ratio.
The other system is always shown alongside.
Length converter
Enter the real-world dimension to scale down.
Scale speed
Model distance the loco travels
How long the pass took
Recommended car weight (NMRA RP-20.1, HO)
Body length, not including couplers
RESULTS
Length
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Also
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Feet + inches
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Scale speed
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Model speed
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Recommended weight
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Also
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Use this as your average car weight in the RailGrade Calc for a realistic pull estimate.
Conversions use the selected scale ratio (HO = 1:87.1). Scale speed converts the model’s travel into the equivalent full-size speed. Weight follows NMRA RP-20.1 for HO (1 oz + 0.5 oz per inch of body length); other scales use different figures.