Calibrating

Last updated 28/05/2026

Overview

Calibration is the process of setting an accurate scale on a drawing so that measurements taken within the system reflect real-world dimensions. It ensures that all quantities, distances, and areas calculated from the drawing are reliable.

Without calibration, any measurement taken from a drawing may be inaccurate due to scaling differences between the original file and its displayed version.

Calibration should be performed when:

• A drawing is first uploaded into the system
• The drawing scale is unknown or unreliable
• Measurements appear inconsistent with known dimensions
• The drawing has been resized, rotated, or converted

Calibration Workflow

For calibration, you need to focus on a known dimension within the drawing. This could be a common reference, such as a door, but in this example, we'll use a known dimension line provided in the drawing.

Start by zooming in on the dimension. There is no snap functionality when working with a drawing that has no geometry applied. Open the Measure tool by right-clicking in the viewport and selecting Measure.

Figure 1 - Measure tool

Left-click at the starting point and drag your mouse to the endpoint. The drawing is not to scale.

Figure 2 - Measurement

Click the Start Calibration button for the layout you are working with to open the Calibration Properties dialog.

Figure 3 - Start Calibration button

This dialog can be easily moved around the viewport, left-click on the dialog header to move the dialog to a position that is not in your way. To activate the measurement mode, click Calculate for the X Factor field.

Figure 4 - Calculate X factor

Move to the starting point of the dimension, then left-click and hold while dragging along the measurement.

Figure 5 - Paper distance measurement

Release at the endpoint, and the measured value will automatically populate in the Paper Distance field as this is the measurement on the drawing.

Figure 6 - Paper distance measurement

Next, repeat this process for the Y Factor field. Click the Calculate button, but this time measure a vertical dimension for the Y factor value.

Figure 7 - Calculate Y factor

Once you have the paper distances calculated, you'll need to enter the real-world distances for both fields. In this case, the drawing shows the known measurement for both X and Y as 5000mm, so these values need to be added into the Real Distance fields.

Figure 8 - Real distance values

Once you're satisfied with the inputs, apply the calibration to update the drawing.

Figure 9 - Apply button

tip

Once the calibration has been applied, use the Measure tool again to confirm the drawing is now correctly scaled and ready for measurements.

Figure 10 - Scaled drawing