Most people re-derive their sizing from scratch on every order. They open a chart, try to remember whether the jacket that fit was a large, look at a stranger's haul photo, and guess. Six weeks later they do it again, having learned nothing they can reuse.
The alternative is one afternoon of work that turns every future size decision into a lookup. Not a spreadsheet of your body — a spreadsheet of your clothes.
This page is about the artefact: what its columns should be, why those and not others, and how to keep it alive across twenty orders. It does not cover where to put the tape. The flat-measure walkthrough already does that.
Let the charts choose your columns
The temptation is to build the sheet a tailor would want: neck, bicep, inseam, rise, back length. Do not. A column that never appears on a seller's chart is a number you will never get to compare against anything.
We hold 57 size charts, read out of images published by one seller and shown per item on the shelf. Between them they use exactly seven measurement names, arranged into two shapes:
- Upper body, on 23 charts: length, chest, shoulder, sleeve.
- Lower body, on 32 charts: length, waist, hip, leg opening.
Two more are near-variants of the upper-body shape. That is the entire vocabulary, and all 57 charts are in centimetres.
So your sheet needs two row templates of four fields each, plus the garment's identity. Eight columns total:
- Garment — what it is, in your own words. "Navy oxford shirt", "black work jeans".
- Type — upper or lower. This picks which four fields you fill in.
- Length
- Chest or Waist
- Shoulder or Hip
- Sleeve or Leg opening
- How it fits — one phrase. "Right", "slightly big, on purpose", "too tight buttoned".
- Measured on — a date.
Centimetres in every cell. Converting inches under time pressure at checkout is where the errors happen.
What goes in it
Not everything you own. Pick the garments that fit the way you want that category to fit — one t-shirt, one hoodie, one knit, one jacket, one pair of trousers is enough to start.
The seventh column is the one people leave out and the one that does the work later. A row reading "chest 58, right" and a row reading "chest 58, too tight buttoned" are the difference between a target and a floor. You will not remember which was which in March.
Using it, which takes about a minute
Runs in this corpus are short: 22 charts offer three sizes, 33 offer four. You are rarely choosing between more than four options.
- Open the chart for the exact album you are buying from, because the same letter is graded per garment rather than per shop.
- Find the row in your sheet for the closest garment type you own.
- Compare on the field that decides: chest for upper body, waist for anything with legs. Shoulder is a veto rather than a choice, and sleeve mathematically cannot break a tie.
- If two sizes land within about three centimetres of each other, the chart's own printed tolerance has eaten the difference and something other than the table has to decide.
- When there is no chart at all — the normal case — send the fields instead. Your sheet is already the list of what to ask for, which is why the request message is so short once you have one.
The sheet is the answer you already needed
Here is what having your own numbers looks like, from a buyer working out a bracelet size:
I measured my wrist size (17.1 cm). The seller is recommending either 18.5 cm or 19 cm. I saw that you went with the 18 cm size. What’s your wrist size, if you don’t mind sharing?
u/Due-Equivalent-575, r/FashionReps, 14 April 2025
Read what that buyer is holding. A measurement of their own. A seller recommendation they can weigh instead of accept. A reference object they already own, and a specific question for someone whose result they can compare against. Every one of those is a row in a sheet — the full thread is linked from the seller's page.
Jewellery happens to be the category where people naturally do this. There is no reason chest and waist deserve less care than a wrist.
Closing the loop, which is what makes it compound
The sheet is worth building on day one. Around order four it becomes worth more than any chart, if you feed it.
- Add the QC measurement. When your agent photographs the item in their warehouse, ask for a tape across the chest or waistband and write that number next to what the chart claimed. After a few orders you have a private record of how far charts drift from objects. Reading QC photos covers what else to ask for.
- Add the outcome. When the parcel lands, measure the item yourself and add a row with the fit phrase filled in honestly. A piece that disappointed you is more informative than one that worked.
- Keep it beside the order record. The size you chose, the number you chose it from, and what arrived belong in one place — keeping order records covers the rest.
Re-measure a reference garment once it has been washed a lot. Fifty of the 57 charts in our set carry the seller's own instruction to rinse jeans in cold water only, and a shrinkage warning from the person selling the garment is also a warning that your own reference row has a shelf life.
What the sheet will not do
It will not size shoes. There is no footwear chart anywhere in the corpus we hold, every field in the set is an apparel field, and a flat tape across a sneaker tells you nothing useful.
It will not let you compare two sellers. Not one of the 57 charts states whether its figures were taken flat across the garment or around the body, so two stores' "chest 63" are not known to describe the same thing — the reasoning is on the methodology page.
And it verifies nothing about a seller. What we publish is their printed numbers linked back to the image. Your sheet is the one part of this process where the numbers were taken by someone you can hold responsible, on objects you can go and look at. That is why it beats every chart you will read.