Bolt

All projects

WorkflowStep 1 of 4

Upload your photo

Place the tool on an A4 sheet and take a top-down photo.

Canvas

Import photo

Drop a photo here or choose a file.

JPEG, PNG, WebP, HEIC Up to 22 MB

Units: mm
100%
100%
Ready
mm

First-time setup

Set this up once. Your saved choices apply to future photos on this browser. You can change them later in Settings.

A4 targets

Print at Actual size / 100%, without Fit to page. Keep both sheets flat on matte, rigid backing.

Print scale

Measure the two 100 mm bars on the work mat with a ruler. A photograph cannot independently verify printer scale.

Optional camera check

Upload one photo of the EMPTY chessboard. Keep the sheet flat and all squares sharp. This checks the board geometry; work-mat markers provide perspective alignment. A single photo does not calibrate lens distortion.

No calibration views added.

    No lens profile. Perspective alignment still works.

    Ready to photograph

    Use the work mat with the blank centre. Keep the tool inside that area and markers on opposite sides visible. Upload the tool photo; alignment and tracing start automatically. Height above the sheet can still affect dimensions.

    Create circle series

    Circles are placed in order without moving existing elements. Each uses the selected circle’s depth.

    Save preset

    Rename preset

    Unsaved preset changes

    Save your changes before choosing another preset?

    New folder

    Move project