Online Ruler

Verify the ruler before measuring an object

Open Calibrate Screen, choose Credit Card and adjust the displayed outline to the width of a standard 85.6 mm card. Save calibration, choose cm or inches and confirm that the card still measures correctly. Recheck after browser zoom, display scaling or monitor changes.

Use the ruler at your current screen scale

Align the object with the zero mark and read the opposite edge. Use inches, cm or mm for a physical object, and pixels for on-screen spacing. Check printed output with its 100 mm reference line and print at actual size.

Multi-Edge Screen Rulers & Full-Frame Layout Canvas

Unlike traditional handheld straight rulers, ToolJiffy Online Ruler lets you place calibrated ruler scales on any or all four edges of your screen simultaneously:

• Top Ruler — Horizontal measuring bar along the top edge.
• Bottom Ruler — Horizontal ruler bar along the bottom edge.
• Left Ruler — Vertical measuring bar along the left edge.
• Right Ruler — Vertical measuring bar along the right edge.

Activating all four edges creates a full-frame measuring canvas — ideal for web designers, illustrators, architects, and crafters laying out physical items directly against their display.

Advanced Feature Suite: Guides, Crosshair, Drag-to-Measure & Overlays

ToolJiffy goes beyond standard ruler lines with powerful interactive tools:

• Drag-to-Measure & Saved Log — Click the Measure tool and click two points on screen to instantly calculate the distance between them. Results are displayed in a badge with 1-click clipboard copy and auto-saved into a scrollable session log.
• Interactive Reference Lines (Guides) — Click anywhere on the screen (or press G) to drop permanent horizontal and vertical reference lines.
• Live Cursor Crosshair (C Key) — Toggle a live crosshairs overlay that follows your cursor, displaying live X and Y coordinates in your selected measurement unit.
• Draggable 180° Protractor (P Key) — Measure angles between 0° and 180° using an interactive semicircle protractor.
• Real-World Object Overlays — Place calibrated outlines of standard items on screen, including credit cards, A4/Letter paper, coins (US Quarter, 1€, UK 50p, Indian ₹10), a Ring Size Guide, and a Kids' Shoe Size Guide.
• 1-Click Printable PDF Ruler — Generate an A4/Letter printable PDF ruler complete with a 100 mm physical verification scale.

Keyboard Shortcuts Reference