You want to know your ring size, you don't want to leave the house to find it out, and you'd rather not guess and get it wrong. Here's how to measure at home in a couple of minutes — and how to know when the number you get can actually be trusted.

The short version: wrap a strip of paper or a piece of string around the base of your finger, mark where it overlaps, and measure that length in millimeters. That measurement is your finger's circumference — match it to the chart below to get your US ring size. If you already own a ring that fits, you can skip the string entirely and measure the ring instead.

Ring Size Chart (US Sizes)

Match your finger's circumference — or the inside diameter of a ring you already wear — to the closest row. If you land between two sizes, size up.

US Ring Size	Inside Diameter (mm)	Inside Circumference (mm)
4	14.8	46.5
4.5	15.3	48.0
5	15.7	49.3
5.5	16.1	50.6
6	16.5	51.9
6.5	16.9	53.1
7	17.3	54.4
7.5	17.7	55.7
8	18.1	57.0
8.5	18.5	58.3
9	18.9	59.5
9.5	19.4	60.8
10	19.8	62.1

Most women's rings fall between a 5 and a 7. Most men's fall between a 9 and an 11. But "most" isn't you — measure, don't assume.

The Two Ways to Measure at Home

Method 1: The paper strip

Cut a thin strip of paper about 4 inches long, or use a piece of non-stretchy string. Wrap it snugly around the base of the finger you're sizing — snug enough that it won't slip off, loose enough to still slide over your knuckle. Mark the spot where the end meets the strip, lay it flat against a ruler, and read the millimeters. That's your circumference. Find it in the chart.

Method 2: Measure a ring you already own

This is the more reliable of the two, if you have a ring that fits the right finger. Lay the ring on a ruler and measure straight across the inside, edge to edge — that's the inside diameter. Match it to the middle column above. A ring you already wear and love has already done the hard part: it's been proven on your hand, in real life.

What Throws Off Your Measurement

Time of day

Your fingers are smallest in the morning and after cold weather, and largest at the end of a hot day or after a workout or a salty meal. The swing can be as much as a full half-size. Measure in the late afternoon, at a normal temperature, when your hands are at their everyday baseline.

Your knuckle

If your knuckle is noticeably larger than the base of your finger, the ring has to clear the knuckle to go on but will spin at the base once it's there. In that case, size to somewhere between your knuckle and your base measurement — not to the base alone. This is the single most common reason a ring ends up too loose.

Band width

A wide band takes up more room on your finger and fits tighter than a thin one at the same size. If you're buying something substantial — a wide diamond band, a dome ring — you may want to go up a quarter to a half size. A thread-thin stacker can stay true to size.

Dominant hand

The fingers on your dominant hand tend to run slightly larger. Measure the exact finger, on the exact hand, that the ring is going to live on.

Why I'd Rather You Not Guess on the Important Ones

For an everyday piece, the home method gets you close enough, and anything half a size off is an easy fix. But for the rings that matter — an engagement ring, a piece we're making for you, something set with a stone that has to sit exactly right — I'd rather have your finger measured properly than have you order blind and hope.

Here's the honest part most sizing guides leave out: not every ring can be resized after the fact. A simple gold band resizes easily. But a full eternity band set with stones all the way around, or a ring with an intricate gallery, can be difficult or impossible to size up without remaking part of it. A band like our East-West Baguette Diamond Band ($1,250) is best ordered to the right size from the start rather than adjusted later. The same goes for a bezel-set engagement ring like the Sunken Set Asscher Engagement Ring ($3,900) — worth getting exactly right before it's made. A ring offered across half sizes, like our Oval Cut Pale Blue Sapphire Dome Ring ($2,500), gives you more room to land on your true fit — but you still have to know what that fit is.

How Sizing Works With Me

If you're local, come in and I'll size your finger on a proper mandrel in thirty seconds — no charge, no appointment pressure, whether you're ordering that day or not. If you're anywhere else in the country, tell me what you measured at home and I'll walk you through confirming it, and I can mail you a simple sizer before we make anything to order. When a piece does need resizing down the line, that's a normal part of owning fine jewelry — fingers change over a lifetime, and most rings are built to change with them.

A Few Questions I Get Asked

What if I'm between two sizes? Size up. A ring that's a hair loose is comfortable and safe; a ring that's too tight is neither, and it's harder on the finger in summer.

Can you resize any ring? Most, yes — usually up or down a size or two. Full eternity bands, tension settings, and some patterned bands are the exceptions. Ask before you buy if resizing is a real possibility for you.

How do I size a surprise gift? Borrow a ring she already wears on the right finger and measure the inside diameter, or trace the inside circle on paper. If you can't, order close and plan on one resize — that's the normal path, and it's fine.

Do fingers really change size? They do — with temperature, time of day, weight, pregnancy, and age. That's expected, and it's exactly why resizing exists.

Get It Right the First Time

If you'd like a second set of eyes before you commit — on your size, on whether a piece can be resized, or on anything you're planning to have made — book a complimentary consultation, in person in Santa Monica or virtually from anywhere in the U.S. It costs nothing and it's the surest way to end up with a ring that fits your finger and your life.

For more on keeping that ring in good shape once it's yours, see how to care for fine jewelry, and if you're planning a custom piece, here's what to bring to a consultation.

Kate Price is the founder of Kate Rose Fine Jewelry, a Santa Monica studio specializing in heirloom redesign and custom fine jewelry.