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).

SHOP FRACTIONS
- Every length is also shown as the nearest 1/16, 1/32 or 1/64 inch, so you can read it straight off a tape.

BUILD A WHOLE PROJECT
- Stack several rings and see total segments and total board length.
- Generate a tapered stack from a top and bottom diameter in one step.
- Save projects by name and reopen them later.
- 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 or share a clean cut list for every ring in the stack.

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.