coneunwrap.One radius, not two sides.
A 100 mm circular diameter means a 50 mm radius. Entering the full diameter doubles the corresponding circumference in the model.
Truncated-cone paper wrap calculator
A curved surface.
A flat beginning.
Turn two circular radii and a slant height into an annular-sector paper pattern. See the developed dimensions, then save a calibrated SVG to test at your own scale.
25 / 50 / 100 mm — THE WORKED EXAMPLE
Unwrap your dimensions
MEASURE RADII · ENTER SIDE LENGTH · TEST THE PATTERN
02 / Your developed pattern
- Developed outer radius
- Developed inner radius
- Calculated vertical height
- Cut-outline bounding size
No seam tab, overlap, end caps, cutting kerf or material-thickness allowance. This is an ideal geometry model.
Fit-to-screen preview — not print scale
The downloaded SVG records millimetres and includes a 50 mm calibration line. Print at 100%, verify the line with a ruler, and check a scrap-paper fit. It may exceed one sheet; automatic tiling is not included.
Assumes concentric circular edges, a straight conical side and zero material thickness. It does not fit uneven, oval, curved-sided or offset objects. Radii are limited to 5,000 mm and slant to 10,000 mm; equivalent limits apply in other units. Inputs accept up to 6 decimal places. SVG curves use bounded polyline approximations, described in the guide. Printer, cutter and material accuracy are outside this model.
Keep the seam in mind.
The straight edges meet with zero overlap. No glue tab is hidden in the result. Plan any joining allowance separately and test with scrap.
Measure the printed check.
Screen previews scale to the window. The saved SVG has physical millimetre dimensions; verify its 50 mm line after printing instead of assuming fit-to-page preserves size.