Maternity Size Chart: How to Read It

To read a maternity size chart, find which measurement the brand uses (usually your pre-pregnancy size, your bust and your hips), then check the brand's notes on stretch and bump room. Maternity sizes are not standard, so the chart on the product page matters more than the label you usually wear.

This guide is for shoppers and covers what the columns mean and how to avoid the most common mistakes. It follows the same logic as AI size recommendation for fashion stores: measure first, then match your numbers to that brand's own chart.

What is different about a maternity size chart?

A regular chart gives ranges for bust, waist and hips. A maternity chart often replaces the waist with a stretch panel, a bump allowance or a pre-pregnancy size.

Three things change:

• The waist is not the main number. Your waist will change through pregnancy, so many brands size by pre-pregnancy size instead.
• Fabric stretch does more work. Ruched sides, jersey knits and side panels are designed to grow with you.
• Labels vary by brand. One brand's medium can be another brand's small, so never assume.

Which measurements should you take first?

Use a soft tape measure and measure over thin clothing. Ask someone to help, and write the numbers down in both centimeters and inches.

1. Bust: around the fullest part of your chest.
2. Under-bust: directly under the bust, useful for dresses with an empire line.
3. Hips: around the widest part of your hips and seat.
4. Bump: around the fullest part of your belly. Only some brands ask for this.
5. Height: without shoes, since length matters for dresses and trousers.

Your body changes week to week, so retake your measurements before each order. Your care provider can answer any health questions. A size chart only covers clothing fit.

How do you match your numbers to the chart?

Start with the measurement the chart actually lists, and ignore the rest.

If the chart gives bust and hips, find the size that fits both. When you fall between two sizes, take the larger one, since stretch fabrics forgive a roomy fit better than a tight one.

If the chart uses pre-pregnancy sizes, pick the size you wore before, then read the brand's note. Some brands say to stay in that size for the whole pregnancy. Others suggest sizing up in the third trimester.

Here is a simple way to read the common column types:

Column in the chart	What it means	What to do
Pre-pregnancy size	The size you wore before	Pick your usual size, then check the fit note
Bust / hips	Body measurements, not garment width	Match your own numbers to the range
Bump or belly	Fullest part of your belly	Choose the size whose range includes your number
Garment length	Length of the item	Compare to a dress you already own
Stretch / fabric	How far the fabric gives	More stretch usually means more room to grow

This is an example layout, so always check your brand's own chart.

How do you choose between two sizes?

Look at fabric first. A stretchy knit usually works in the smaller size for longer. A woven fabric, such as cotton poplin, has no give, so choose the larger size.

Next, think about timing. If you are buying early for a baby shower photo, you may be fine in a smaller size. If you are buying for the last weeks, size up.

Finally, read the fit note and the reviews that mention bump size. Reviewers who describe their own height and stage are the most useful.

What should you check by garment type?

Each type of maternity clothing uses the chart a little differently.

• Dresses: check bust and hips, then the length. A dress that fits over the bump can still ride up if it is too short.
• Tops: look at the bust and the fabric stretch. Check whether the hem is long enough to cover the bump.
• Leggings and trousers: see whether the waistband sits over or under the bump. Over-bump bands are measured differently from low-rise bands.
• Nursing wear: a bust and under-bust measurement matters more, since your chest changes too.

Write down the garment type next to your numbers when you shop, so you do not mix up charts between categories.

Where can a store help you choose?

Some stores add a "Find my size" step to their product pages. With ZeDaq.ai, the shopper uploads one photo and types their height, and the store's own size chart supplies the labels. Ask the brand if its chart suits pregnancy before you rely on any tool.

Store owners who sell maternity wear can also tighten their own charts. The guide on fixing a size chart after returns spike shows how to find the columns that cause trouble.

How do other size charts compare?

Reading a chart is a skill that carries across categories. If you buy for others too, these guides show the same method for men's trouser size charts and plus-size women's charts.

FAQs

Should I buy maternity clothes in my pre-pregnancy size?

Often yes, if the brand sizes that way. Check the chart, since some brands expect you to size up later.

Do maternity sizes match regular sizes?

Not always. Each brand sets its own sizes, so compare your measurements, not just the label.

Is it better to size up in maternity wear?

If you are between sizes, the larger one is usually safer, especially in non-stretch fabric. Stretch knits can stay in your usual size.

Can I return maternity clothes if the size is wrong?

That depends on the store's return policy. Read it before you buy, and keep tags on until you have tried the item on.