LEGO MOC Scale Checker

The LEGO MOC Scale Checker is a free in-browser tool that calculates the scale of your LEGO model by comparing your model's dimensions to the real-world subject it represents. It checks each axis (length, width, and height) for proportional accuracy and tells you exactly how far off each dimension is and what the ideal size should be.

Your model dimensions can be entered in studs, plates, bricks, centimeters, or inches (per axis independently). So you can enter your length in studs and your height in plates, for example, without any conversion needed.

Tolerance is how much deviation from the reference scale is acceptable before a dimension is flagged.

• Strict (5%) is for builders who want maximum accuracy.
• Standard (10%) is suitable for most display models.
• Relaxed (15%) or Loose (25%) work well for microscale builds where the brick system inherently limits precision.

If you leave the target scale blank, the tool averages the scale across all your provided dimensions and uses that as the reference. If you enter a target scale (say 1:1000) the tool checks every axis against that specific scale, telling you what needs to change to hit your intended scale precisely.

Unless your model is perfectly proportioned, each axis will have a slightly different calculated scale. A ship that is correctly scaled on length but too narrow on beam will show 1:1000 for length and 1:1800 for width, for example.

This per-axis breakdown is exactly the point of this tool as it tells you which dimensions need correcting and by how much.

Exactly what they mean actually.

These refer to the model dimension relative to the reference scale. "Too large" means that axis is built at a larger scale than the reference, the model part is proportionally oversized.

"Too small" means that axis is built at a smaller scale, the model part is proportionally undersized. Both include the percentage deviation so you know how significant the error is.

The ideal size shows what your model's dimension should be at the reference scale (in both studs and centimeters or inches for imperial input). This gives you a concrete target: how many studs to add or remove to bring that dimension into proportion.

Yes! Ships, submarines, aircraft, vehicles, buildings, trains, spacecraft, or anything with real-world reference dimensions.

The tool is subject-agnostic. Enter any real-world measurements and any model measurements and it works the same way regardless of subject.