How to answer "what size should I get?"
"I'm usually a 12, what size should I get?" is a message every clothing, shoe and accessories shop knows well. The customer has already chosen the item. The only thing standing between them and the checkout is a worry that it will not fit. Answer it well and you get the sale and, just as importantly, avoid a return. Answer it with a guess, or with "check the size guide", and they either leave or order two sizes and send one back. This guide covers the questions worth asking, replies for the situations you meet most, a worked example, how to turn your size guide into words an AI agent can use, and when to let a person decide.
The short answer
Ask for one or two facts that really change the answer, such as their usual size in a brand they know and how they like things to fit. Then give a clear recommendation with the reason, using real measurements from your own size guide. Finish by telling them how easy it is to exchange, so the decision feels safe.
Replies you can adapt
Change the details to match your business. Names, prices and times are examples.
| When | Reply |
|---|---|
| They give their usual size | Thanks, Amira. This dress comes up quite true to size, so a 12 should fit you well. If you are between sizes or like a looser fit through the waist, a 14 would give you a little more room. |
| You need one more detail | Happy to help. Could you tell me your usual size in a high-street brand, and whether you like a fitted or a relaxed look? Then I can tell you which size people with a similar fit usually choose. |
| Between two sizes | If you are between a medium and a large, I would go with the medium for a neat fit or the large if you want to layer a jumper underneath. The chest on the medium is 104cm and on the large it is 110cm. |
| It runs small or large | This one runs about half a size small, so most people choose one size up from their usual. If you are a 6 in most trainers, a 6.5 is the safer choice. |
| They compare with another brand | I cannot speak for every brand, but our jeans are cut slightly roomier than most. If a 30 waist fits you well elsewhere, a 30 here should feel comfortable rather than tight. |
| They send their measurements | Thank you for the measurements. With a 96cm chest, the small would fit closely and the medium would be relaxed. As it is a knit, it will soften a little with wear, so I would suggest the small. |
| They ask for a specific body | That is a great question, but I would only be guessing from a photo. If you have a jacket you love the fit of, measure it flat across the chest and I will compare it with ours. |
| The fit is a gift | For a gift, I would go for the size they usually wear and include a gift receipt. Exchanges for a different size are free within 30 days, so they can swap it easily. |
| Out of hours | Thanks for your message. The size guide is here: [link]. I will look at your question properly first thing tomorrow and reply by 10am with a recommendation. |
What to avoid
- Replying "check the size guide" and nothing else. They usually already have, and it did not answer their worry.
- Promising "it will fit you perfectly". You cannot know, and it makes a return feel like your fault.
- Asking for photos of the customer's body. Measurements of a garment they already own are more useful and far less awkward.
- Giving a different answer to every customer for the same item. Agree one line per product and stick to it.
- Letting an AI agent invent how an item fits when the size note says nothing about it.
What to tell your AI agent
- Give it a size note for each item or range: the measurements, whether it runs small, large or true, and the fabric.
- Tell it to ask at most two questions before recommending, and to always give the reason for its choice.
- Tell it to mention your exchange policy in plain words at the end of every sizing reply.
- Tell it never to describe a fit that is not in the note, and to say a person will check instead.
- Ask it to pass questions about medical needs, adaptive clothing or unusual fit to a person.
When a person should take over
- Bespoke, made-to-measure or altered items, where the size decides the whole order.
- A customer who has already returned the item once for fit.
- Questions about fit for medical or accessibility reasons.
What the customer is really asking
A sizing question is a question about risk. The customer is trying to work out whether ordering is a good bet. They want to know what you would choose in their place, and what happens if you are both wrong.
That is why the exchange line matters as much as the size. "A 12 should fit, and swaps are free within 30 days" answers both halves of the worry. The customer can say yes without feeling they are gambling.
It also helps to remember that sizing messages come from people who are close to buying. They have chosen the item, often the colour too. A fast, confident reply here is worth more than almost any other message in your inbox.
The two questions that do most of the work
You rarely need more than two facts to give a good size recommendation. Asking more slows the conversation and can feel like an interview.
| Type of product | Question one | Question two |
|---|---|---|
| Dresses, tops and knitwear | Your usual size in a brand you know | Fitted or relaxed? |
| Jeans and trousers | Usual waist and leg length | Do you like high or mid rise? |
| Shoes and trainers | Your usual size in a named brand | Narrow, regular or wide feet? |
| Rings and bracelets | A ring size, or the inside width of one they own | Which finger or wrist? |
| Children's clothes | Age and height | Room to grow, or a neat fit now? |
If the customer has already given you the answer to both, skip straight to the recommendation. Nothing frustrates people more than being asked something they have just told you.
A worked example
A small knitwear brand gets this conversation on Instagram. The AI agent answers from the owner's size note and hands an unusual request to the owner. Names and details are examples.
| Who | Message |
|---|---|
| Customer | Hi, love the cream cardigan! What size should I get? |
| Business | Thank you! Could you tell me your usual size in a high-street brand, and whether you like it fitted or quite slouchy? |
| Customer | Usually a medium, but I like it oversized |
| Business | The cardigan is already cut loose, with a 112cm chest on the medium. Most people who want an oversized look stay with their usual size, so I would suggest the medium. If you want it really roomy, the large has a 118cm chest. Swaps are free within 30 days if it is not right. |
| Customer | Perfect, medium it is. Is the sleeve long? I have long arms |
| Business | Good question. The sleeve on the medium is 58cm from the shoulder. I have asked Hannah, who makes them, whether she can add length, and she will reply this afternoon. |
| Owner | Hi, Hannah here. I can add 4cm to the sleeves for no extra charge, but it adds two days to making it. Would you like that? |
The agent gave a real measurement, a recommendation with a reason and the exchange policy. It did not guess about the alteration, which only Hannah could agree to.
Turn your size guide into a note your agent can use
A size chart on your website is a grid of numbers. A customer, and an AI agent, need the story behind it: how each item really fits and what most people choose. Write it once and keep it next to your product list.
- List each item or range, with the key measurements for each size.
- Say plainly whether it runs small, large or true to size.
- Write down what most customers choose, and why, from your own sales and returns.
- Note the fabric and whether it stretches, shrinks or softens.
- Add your exchange policy in one sentence.
- Put the date at the top and update it when a new batch fits differently.
Size note, updated 1 November
Cream cardigan: loose cut. Chest S 106cm, M 112cm, L 118cm. Sleeve M 58cm.
Most people stay with their usual size. Size up only for a very roomy look.
Wool blend, softens with wear, does not shrink if washed cool.
Ribbed jumper: fitted, runs slightly small. Most people size up one.
Exchanges: free within 30 days if unworn, tags on.
Rules:
- Ask at most two questions: usual size and how they like it to fit.
- Always give the measurement behind your answer.
- Never describe a fit that is not written here. Say Hannah will check.
- Alterations, longer sleeves or custom sizes: hand to Hannah.If this happens, do this
| Situation | What to do |
|---|---|
| They order two sizes to try | Thank them, explain the exchange or return steps, and check the size note for which one to suggest keeping. |
| Your size note says nothing about this item | Say you will check and reply by a set time. Measure the item yourself and add it to the note. |
| Many people ask about the same item | Add one line to the product page, such as "runs small, most people size up". |
| The item came back for fit | Ask what was wrong, recommend the other size with the reason and add what you learned to the note. |
How Spaces fits in
Spaces connects your own Instagram, WhatsApp, Messenger and email accounts to the AI agent you already use, so it can answer sizing questions in the chat the customer started. It does not connect to your shop or your size chart itself. The agent answers from the size note you give it, or from your shop if you have set that up through its own tools.
Replies go out at a human pace. On Instagram, Spaces waits at least 15 seconds between messages. If you would like to see every recommendation before it is sent, ask your AI agent to hold replies as drafts, and nothing goes out until you approve it.
Sum up and next step
Ask one or two useful questions, recommend a size with the reason behind it, and end with your exchange policy. That turns a nervous customer into a confident one, and fewer parcels come back.
Spend half an hour writing a size note for your best-selling items today. It will make your own replies faster and give your AI agent everything it needs.
Pricing
FAQ
Should I just send a link to the size guide?
Send it with a recommendation, not instead of one. Most people asking have already looked at the guide and still feel unsure. A one-line answer such as "a 12 should fit, and the chest is 92cm" is what settles it.
What if I recommend the wrong size?
It happens, and an easy exchange makes it a small problem. Thank them for letting you know, swap it quickly and add what you learned to your size note so the next answer is better.
Is it fine to ask for measurements?
Yes, as long as you ask for simple ones and explain why. Measuring a garment they already love, laid flat, is often easier for the customer than measuring themselves. Avoid asking for photos of their body.
Can an AI agent answer sizing questions?
Yes, if it has a clear size note with measurements and real fit notes for each item. Tell it to ask no more than two questions, give its reason and never describe a fit that is not in the note.
How do I handle "I'm a size 10 in Brand X"?
Use what you know about your own cut. If your items run roomier or smaller than most, say so. You cannot speak for every brand, so it is fine to say that and ask for a measurement instead.
Should I offer free exchanges for size?
Many small shops find it worth it, because it removes the main worry that stops people ordering. If you cannot offer it, say clearly what an exchange costs so there are no surprises.
What about children's sizes?
Ask for age and height, and whether the parent wants room to grow. Children's sizes vary a lot between brands, so height is usually more useful than age alone.
How quickly should I reply to sizing questions?
As fast as you can. The customer is often on the product page with the item in their basket, and a slow answer gives them time to go elsewhere. A quick reply from your AI agent, with a person stepping in for unusual cases, works well.