How much ballast do I need for OO gauge track?

A typical OO gauge layout uses approximately 40ml of ballast per metre of single track for a main line profile. Double track uses roughly double that. A 2m x 1m layout with 6m of track needs approximately 240ml of ballast, or about half a standard 500ml bag.

What type of ballast should I use?

Use real granite chippings in the correct grade for your scale. For OO gauge, use fine grade (around 1mm). For N gauge, use extra fine. Avoid coloured craft sand as it looks unrealistic. Limestone ballast is available for pre-grouping era layouts.

How do I fix ballast in place?

Apply dry ballast, shape it with a brush, then fix with diluted PVA glue (50:50 with water plus a drop of washing-up liquid to break surface tension). Apply the PVA mixture with a dropper or spray bottle. Allow 24 hours to dry fully before running trains.

How wide should the ballast shoulder be?

Main line ballast extends about one sleeper length beyond the track on each side. Branch line ballast is narrower with a steeper shoulder. Yard and siding ballast is often minimal, sometimes barely covering the sleeper ends. Our calculator adjusts for each profile.

ModelCalcs

Ballast Quantity Calculator — Ballast for Model Railway Scenery

Calculate ballast volume, weight, PVA glue and bags needed for model railway track by scale and profile.

Track Length

Total length of railway track

Track Type

Select the type

Scale

Select the model scale

Ballast Profile

Select an option for ballast profile

How We Calculate This

This calculator estimates ballast quantities based on track dimensions at your chosen scale, with adjustments for track type, ballast profile and shoulder width.

The formula

Volume = Track width x Depth x Track length x Profile factor

Weight = Volume x Ballast density (approx. 1.5g/ml)

PVA glue = Volume x 0.3 (diluted 50:50 with water)

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.