🖥️ Screen Ruler
Drag to measure anything on screen — pixels, cm, mm & inches
🖥 Detecting PPI…
⚙ CALIBRATE
📏 Line Mode — drag to measure
Screen–
PPI–
1 cm =– px
1 in =– px
PX0px
CM0.00cm
MM0.0mm
IN0.000″
🖱 Drag on canvas to measure
📌 Saved Measurements
No saved measurements yet
💡 Tip: Drag for Line/Rect — click three points for Angle. Save any measurement for later.
onlineruler.online — Free & No Download Required
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💳 Credit Card Calibration
Place a standard credit/debit card flat against your screen, then measure its width using Line mode.
1
Close this dialog and switch to Line mode.
2
Drag from the left edge to the right edge of the card.
3
Click “Calibrate to Card” that appears below the canvas.
Standard card size: 85.6 mm × 53.98 mm (ISO 7810)