How to use the length measurement
Align two guides with the ends of a small object to read its length without counting ruler divisions. This tool is useful for stationery, small parts and other items with clearly visible edges. Physical accuracy depends on your screen calibration.
How to measure a length
Calibrate the display, then align the left handle with the start of your object and the right handle with the end. The shaded region shows the measured distance. Drag inside the region to move both guides together while keeping their separation.
Set a reference length
Enter a number in the length field to display a reference interval, such as 3 cm or 1 inch. This is useful when comparing small objects with a known length. Values larger than the display are still calculated, but part of the shape extends beyond the screen.
Improve the alignment
Look straight at the screen and align with actual edges rather than shadows. Use Tab to focus a handle and the arrow keys to make small adjustments. This tool measures horizontal distance, so position the object horizontally before reading the result.
Continue beyond the screen with marks
Calibrate first, align the end handle with the end of your object or a continuation point, and choose “Mark & continue.” The section is saved and the endpoint returns to the left start guide. Move that same point on your object to the left guide and measure the next section. Total length includes saved sections plus the current section. “Use right edge” moves the endpoint to the usable edge; “Undo mark” restores the previous section. Avoid gaps or overlaps when repositioning the object.
A few common questions
Can I measure a long object like a tape measure?
Yes. Calibrate, mark each measured section, reposition that point on the object at the left start guide, and continue. Alignment errors may accumulate across repeated moves.
Can I see centimeters and inches together?
Yes. The length tool shows both units. You can also switch the main input and display unit in the toolbar.