Online Ruler

Use your screen as a virtual ruler. Calibrate it to your display's actual DPI for accurate centimeter and inch measurements.

⚙️ Calibrate Screen (optional — place a credit card/ID on screen and adjust)

Common: 96 (HD), 110 (FHD), 144 (QHD 1440p), 163 (4K 24")

Click on the ruler to place measurement markers.

How to Use the Online Ruler

To get accurate measurements, first calibrate the ruler by entering your screen's DPI (dots per inch). You can typically find this in your display settings. Most Windows HD displays are 96 DPI, while newer high-resolution displays range from 110 to 227 DPI.

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