Sizing
Your size.
Two ways to measure at home, and each takes about two minutes. It's worth measuring twice.
Measure the finger you'll wear it on. A spinning ring is often worn on the index or middle finger, and those are usually a size or two larger than your ring finger.
Measure straight across the inside of a ring that fits, edge to edge.
Cut a thin strip of paper, about 5mm wide. Wrap it round the base of the finger, snug but not tight, mark where it overlaps, then lay it flat and measure to the mark.
How it should feel. The bands should turn freely while the ring itself stays put, and it should need a gentle push to come back over the knuckle. If it slides off on its own, it's too big. If the whole ring turns with the bands, it's too tight.
Measure at the end of the day. Fingers are smaller in the morning and in the cold.
Checking your ruler: a bank card is 85.6mm along the long edge.
Print it
A sizer you can print.
Print this page at 100%, with no scaling or fit to page.
Step one, check the print
Hold a bank card against the box above. If the box is not exactly the width of the card, your printer has scaled the page and the circles will be wrong. Print again with scaling set to 100%.
Or measure a ring you own
Lay a ring that fits over the circles until one matches the inside edge.
Questions
About sizing.
Which finger is it worn on?
Usually the index or middle finger, because they're easiest to reach with your thumb. They're often a size or two larger than your ring finger, so measure the one you'll wear it on.
What if I'm between sizes?
Size up. The bands need a little room to turn.
Do wide rings fit differently from thin ones?
Yes. A wide band covers more of your finger, so it sits snugger than a thin band of the same size. If you measured a thin ring you already own, go one size up.
Can it be resized?
No. The outer bands are closed loops made to fit the base band, so changing the base would leave them the wrong size. That's why it's worth measuring carefully before you order.
How accurate does the measurement need to be?
To within about a millimetre. Our sizes are about 2.6mm apart, so half a millimetre either way won't change your size. If your knuckle is much wider than the base of your finger, measure both and go between the two.