Online Rectangle Measurement: Length & Width

Match the adjustable rectangle to a rectangular object or on-screen area and read its horizontal and vertical dimensions.

Outil rectangle actif
Rectangle
Longueur et largeur
Non calibré

Quick Usage

01. POSITIONNER LE RECTANGLE

Position the rectangle

Move the rectangle so its starting corner lines up with the corner of the object or area you want to measure.

02. AJUSTER LES CÔTÉS

Adjust each dimension

Change the horizontal and vertical dimensions independently until the rectangle matches the object or area.

03. LIRE LES DIMENSIONS

Read the result

The tool shows the two measured dimensions in cm, mm, inches, or pixels and updates them as you adjust the shape.

Length and Width

The rectangle tool measures two perpendicular sides independently. Use it when you need the dimensions of a card, box, photo, sheet, screen region, or another rectangular shape.

Measuring a Physical Rectangle

Calibrate the display before using cm, mm, or inches as physical dimensions. Then align the rectangle's corner and two sides with the physical object as closely as practical.

Keep the Rectangle Aligned

The measurement box follows the screen's horizontal and vertical directions. If the physical rectangle is rotated, measure an individual edge with the Line tool or reposition the object before using the rectangle tool.

What Can Affect the Reading

Physical results can be affected by calibration, browser zoom, display scaling, viewing angle, and small alignment errors. Use the rectangle tool for practical checks and verify important dimensions with a suitable physical measuring instrument.

Frequently Asked Questions

Questions fréquentes sur la longueur, la largeur, les objets rectangulaires réels et la mesure 2D.

Can I change the two dimensions independently?▼
Yes. The horizontal and vertical dimensions can be adjusted independently.
Can I measure a rotated rectangle?▼
Not directly with the current axis-aligned measurement box. Reposition the object so its sides match the screen axes, or measure individual edges with the Line tool.
Can I measure a physical card or box?▼
Yes. Calibrate the display first, then match the on-screen rectangle to the object's corner and edges.
Do I need calibration for pixel measurements?▼
No. Pixel measurements use the screen coordinate system directly. Physical cm, mm, or inch measurements require a calibrated scale.
Does the rectangle tool calculate area?▼
No. The current rectangle tool reports the two side dimensions.