Screen Ruler

Measure anything on your screen in pixels, centimetres, or inches. Drag and resize the ruler — no install required.

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How to Use the Screen Ruler

Choose Ruler mode for linear measurements or Box mode for 2D area measurements. Drag the ruler or box anywhere on the measurement area. Resize by dragging the handles on either end (Ruler) or the 8 edge/corner handles (Box). Toggle between pixels, centimeters, and inches using the unit buttons. If you need accurate physical measurements, use the DPI Calibrate button and align a standard credit card to the on-screen outline.

About This Tool

Measure anything on your screen with a draggable, resizable ruler or measurement box. Supports pixels, centimeters, and inches with DPI calibration for accurate physical measurements. No download or install required — runs entirely in your browser. Useful for designers, developers, and anyone who needs to measure UI elements, images, or screen distances. Pair with Image Resizer to resize images to specific pixel dimensions or Image Cropper to crop to exact sizes.

Quick Reference Table

Shortcut	Action
R	Switch to Ruler mode
B	Switch to Box mode
U	Cycle unit (px → cm → in)
C	Copy measurement to clipboard
Arrow keys	Nudge ruler/box by 1 px
Shift + Arrow	Nudge by 10 px

Frequently Asked Questions

How accurate are the centimeter and inch measurements?

Accuracy depends on your screen's DPI. Use the Calibrate button with a standard credit card (85.6 mm wide) to set your screen's true DPI. Without calibration, the tool estimates DPI from your browser, which may be off by 5–15%.

Does this upload anything to a server?

No. The ruler runs entirely in your browser with pure JavaScript and the Canvas API. Nothing is sent to any server.

Can I measure elements on other websites?

The ruler measures within the tool's measurement area. To measure other websites, take a screenshot and compare dimensions, or use the pixel measurements as a reference.

Does it work on touchscreens?

Yes. Touch drag and pinch gestures are supported for positioning and resizing the ruler and measurement box.

Can I use keyboard shortcuts?

Yes. Press R for Ruler mode, B for Box mode, U to cycle units, C to copy the measurement, and arrow keys to nudge the ruler by 1 pixel (Shift+Arrow for 10 pixels). These shortcuts make precise positioning much faster.

Created by The Toobits Team · Engineering & Editorial

Toobits is built, tested, and maintained by a small independent engineering team. Every tool is written in TypeScript, runs entirely in the browser, and is reviewed against its source formulas before publication.

Editorial policy · Updated April 2026

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