Online Screen Ruler

Precisely measure objects on your screen, supporting multiple units

Screen Ruler Instructions

This is a precise ruler tool that can be used directly on your screen to help you measure the size of objects. It supports multiple units including centimeters, inches, pixels, and can be automatically calibrated according to your screen DPI.

Multiple Units

Supports various measurement units including centimeters (cm), inches (inch), and pixels (px)

Precise Calibration

Calibrate using standard objects like credit cards to ensure measurement accuracy

Rotation Function

Supports both horizontal and vertical measurement directions

Mouse Position: 0 cm
Measurement: 0 cm

How to Calibrate Your Screen

To get the most accurate measurement results, you can calibrate using a standard object:

  1. Prepare a standard credit card (size: 85.60 × 53.98 millimeters)
  2. Place the credit card on your screen
  3. Adjust the DPI value until the size shown on the ruler matches the actual size of the credit card
  4. Click the "Calibrate DPI" button to save the settings

Note: Different screens and devices may require different DPI settings. The calibrated settings will be saved in your browser.