📏 Digital Screen Ruler

High-precision on-screen ruler with real-world physical calibration (credit card / PPI), dual movable markers, and unit conversions.

Millimeters 0.00 mm

Centimeters 0.00 cm

Inches (Decimal & Fraction) 0.00 in

Pixels 0 px

📐 Interactive Protractor

Interactive angle measurement tool with radial degrees, radians, trigonometric values, and supplementary angles.

Angle (θ): degrees (°)

Degrees (θ): 45.00°

Radians: 0.7854 rad (0.2500 π)

Complementary (90° - θ): 45.00°

Supplementary (180° - θ): 135.00°

Slope / Pitch (Grade): 100.0% (1 : 1)

sin(θ) 0.7071

cos(θ) 0.7071

tan(θ) 1.0000

Classification Acute Angle

Interactive Cartesian coordinate canvas. Plot points, measure distances, and calculate polygon area via Gauss's Shoelace formula.

Click or tap on the grid to add polygon vertices.

X: Y:

X: 0.00, Y: 0.00

Shoelace Polygon Area 0.00 sq units

Perimeter 0.00 units

Centroid (X, Y) (0.00, 0.00)

#	X	Y	Action

Is it free?

Yes. No account is required.

Is my data uploaded?

Calculations run in your browser and require no database.

Does it work on mobile?

Yes, the interface is responsive.