Tools you might need next
Calculate glaze batch weight from unity formula and raw material analysis. Scale recipes to any batch size for consistent studio pottery glazing.
Create kiln firing schedules with ramp rates, hold times, and cone temperatures. Plan bisque and glaze firings for electric and gas pottery kilns.
Calculate clay shrinkage percentage from wet, dry, and fired dimensions. Plan pottery sizes accurately for clay bodies from leather-hard through glaze firing.
US ring sizes are based on inner diameter. Convert size to circumference, which equals the inner arc length of the formed band.
Circumference = π × inner diameterMetal thickness affects the neutral axis during bending. Add a small correction based on band width and gauge so the finished inner diameter matches the target size.
Blank length ≈ π × (inner diameter + metal thickness)Sheet gauge (AWG or B&S) maps to decimal inches or millimeters. Use actual caliper-measured thickness for precision work with rolled or drawn stock.
Blank length = π × (ID + thickness) for medium-width bandsUpdated: July 2026
US size 7 = 17.3 mm ID. A 4 mm wide × 1.0 mm thick band needs a blank of π × (17.3 + 1.0) ≈ 57.5 mm before soldering and rounding.
Size 10 comfort-fit (19.8 mm ID) at 8 mm width and 1.5 mm gauge. Wider bands may need 0.5–1 mm extra length for springback after forming.
Fabricated rings sized on mandrel after soldering. Calculate blank for target size minus ~0.25 size for filing and finishing losses on thin bands.
Ring size is always inner diameter. Using OD overestimates blank length and produces a ring that runs large after forming.
A tight butt joint loses negligible length, but file-fit gaps and excessive solder can shrink effective circumference. Cut blank slightly long and trim if needed.
A ring blank must be the correct arc length before forming and soldering. This calculator converts finger size, band width, and metal thickness into the flat strip length needed for a perfectly sized seamless band.