Res:— PPI:—
Physical:—
Draw
╱ Line
▭ Rectangle
□ Square
△ Triangle
○ Circle
〜 Freehand
Unit
⊕ New Calibration
No saved calibrations
Labels Always
Click 3 points: vertex → arm1 → arm2
📏 Scale Calibration Active
Lay ruler on screen, draw along any section.
Any length that fits is fine.
0 px
⊹ Select Mode — click · Shift+click · drag to box-select · drag shape to move · drag corner handle to resize
2 selected
Measurements
Switch to ⊹ Select mode, then click any shape
Type: —
ID: —
Elements 0
Tool: Line XY: — PPI: —
NOT CALIBRATED

Calibration Wizard

Step 1 of 3

Choose Calibration Method

Pick the reference that matches what you have physically available.

💾 Saved Calibrations auto-saved per device ▾
No saved calibrations yet.

Select Reference Object

Choose the item you will place flat on your screen and trace its edge.

Next: Click Start Drawing, then draw a line that exactly matches your object's edge.

Ruler Calibration

Your ruler may be longer than the screen — that's fine. Draw along any section that fits, then tell us how long that section was.

How it works
Screen
→
Draw line
→
Enter 12.5 cm
Example: 30 cm ruler on a 15 cm screen. Draw from 0 to 12.5 cm mark, then enter "12.5" below.
Next: Click Start Drawing, lay your ruler on screen, draw along any section, then enter the cm.

Known Dimension

Enter the real-world size you will draw on screen, then draw a line of exactly that length.

Tip: Works great for PCB edges, connectors, or any component with a known width.

Enter Screen PPI

Type your display's PPI directly. Check your monitor's spec sheet or manufacturer page.

Common values: 96 (desktop 1×), 144 (1.5×), 192 (Retina), 264 (MacBook), 326–460 (phones).

Draw Reference Line

Tap the floating banner to come back after drawing.

Status: Waiting — tap the banner above to return after drawing.
Drawn (px)—
Reference—
New PPI—
Screen size—