SegmentCalc: Woodturning

SegmentCalc is the calculator for segmented (staved) woodturning. Enter your segment count and finished diameter and get the exact miter angle and segment sizes, so your rings glue up tight with no gaps.

CUT WITH CONFIDENCE
- Miter angle for any number of segments, to two decimals.
- Outer and inner edge length for each trapezoid segment.
- Inner diameter and segment (wedge) angle at a glance.
- Board length needed per ring, with an optional saw kerf allowance.

MEASURED THE RIGHT WAY
- Diameters are measured across the flats (flat-to-flat) - the finished turned diameter, not the corners - matching how woodturners actually size a ring.
- The formula is shown right on screen: outer edge = OD x tan(180 / n).

BUILD A WHOLE PROJECT
- Stack several rings and see total segments and total board length.
- Add a board rate to estimate material cost.
- Work in inches or millimeters; switch any time and your sizes convert.

QUICK REFERENCE BUILT IN
- Miter-angle table for common segment counts.
- Plain-language glossary and a diagram of how diameter is measured.
- Copy a clean cut list to share or paste into your notes.

MADE FOR THE SHOP
- Big, high-contrast display.
- Buy once. No subscription. No ads. Works completely offline, with nothing to sign in to and no data leaving your device.