Instagram Size and Fit Answers From Your Size Guide

By Alva Chew 5 min read Updated November 11, 2026

Size and fit on Instagram means a shopper who asks “what size should I get?” under a post or in your DMs gets one clear size with the reason. AeroChat asks for the measurements your size guide uses, matches them to your size guide and fit notes, checks that size is in stock in your Shopify, WordPress with WooCommerce or Wix store, and sends the link for the right variant.

What happens today

“I’m 5’4”, what size?” sits in the comments under a reel, next to ten more like it. Someone answers from memory, or pastes a link to the size chart, and the shopper still has to work it out alone.

When the answer is late or vague, the shopper orders two sizes and returns one, or doesn’t order at all. The same fit question gets answered by hand again under the next post.

How it runs on Instagram

  1. A shopper asks about size in a DM, a story reply or a comment. For a comment, AeroChat replies privately and continues in DMs.
  2. It finds the product they mean in your catalog, from the post they replied to or by asking.
  3. It asks for the one or two measurements your size guide uses for that product, or the size they wear in a brand they know.
  4. It matches them to your size guide and your fit notes, such as “this style runs small”, and adds what buyers say about fit if you use a reviews app.
  5. It recommends one size with the reason in one sentence. Between sizes, it explains the difference in fit.
  6. It checks that size and color are in stock and sends the link for that variant, or a payment link if the shopper wants to buy in the chat.
  7. If the shopper wants an alteration or a custom size, it hands the conversation to your team with their measurements.

The recipe

Copy this into AeroChat

When a shopper on Instagram asks which size to choose, follow these steps.

  1. Find the product they mean. If they replied to a post or story, use that product. If not, ask.
  2. Ask for the measurements our size guide uses for that product, or the size they wear in a brand they know.
  3. Match them to our size guide and the fit notes in our knowledge base. The Linen Wrap Dress runs small, so suggest one size up (example).
  4. Recommend one size and give the reason in one sentence. If they are between sizes, explain the difference in fit.
  5. Check that size and color are in stock. If not, offer the closest variant in stock, or ask whether they want to hear when it is back.
  6. Send the product link for the variant they chose. If they want to buy now, create the order and send a payment link.
  7. If they ask for an alteration or a custom size, hand the conversation to our team with their measurements (example).

Never guess a measurement that is not in our size guide. Reply in the customer’s language.

Add your size guide and your fit notes for each product line to the knowledge base before you paste it.

Connect the systems behind it

  • Judge.me, Okendo and Yotpo Reviews: add what buyers say about fit, such as “runs small”, to the size advice.
  • Google Sheets: products, variants, stock and measurements for sellers who run their store from a Sheet.
  • Airwallex: built in. Sends the payment link in the DM and confirms the payment to AeroChat.
  • Shopify, WordPress, Wix and Instagram catalogs. Built in. AeroChat reads products, variants and stock directly.

Using a different system? If it has a public API, it connects to AeroChat the same way: describe what you want, paste in its key, and it runs.

Can’t find your tool? Message us in the chat on this page and we’ll tell you how it connects.

Meta’s rules on Instagram

A business can message someone on Instagram only after they message first, and automated replies must go within 24 hours of their last message. That covers the questions, the size advice and the link. A comment allows one private reply within 7 days of the comment, so a size question under a post can move to DMs. A person on your team can reply by hand within a separate 7-day window, which is not for automated replies.

Also on WhatsApp, Messenger and web chat

The same workflow runs on WhatsApp, Facebook Messenger, TikTok Shop buyer chat, Telegram, web chat and email, from the same size guide and the same stock. See the size and fit workflow across every channel.

Who uses it

  • Fashion stores: one size recommended from the shopper’s measurements and your fit notes.

For your store platform: size and fit on Shopify, WooCommerce and Wix.

Questions

Can AeroChat answer size questions in Instagram comments?

Yes. It sends one private reply to the comment and gives the size advice in DMs, where it can ask for measurements and send the link.

Where does the size advice come from?

From your size guide and the fit notes you add to the knowledge base, plus your reviews app if you connect one. It does not guess a measurement your guide doesn’t have.

Will it recommend a size that is sold out?

No. It checks stock for the size and color before it sends the link, and offers the closest variant in stock if that size is gone.

Can the shopper buy in the DM?

Yes. AeroChat creates the order for the chosen variant and sends a payment link. Payment is detected automatically, so the shopper never has to say they paid.

Give every shopper one clear size

Start your 7-day free trial. No credit card needed.

On Shopify? Install AeroChat from the Shopify App Store.

Related: product questions and returns and exchanges on Instagram.