Start With Your Own Measurements, Not the Label

The single biggest mistake people make when shopping for plus-size clothes online is trusting the size they wear in one shop and assuming it will mean the same thing somewhere else. It won't. A size 20 in one brand can fit like a 16, and the same number in another can feel closer to a 24. Labels are marketing, not measurements. Your tape measure is the honest one.

Before you open a single tab, take five minutes to measure yourself properly. Wear the underwear you would normally wear under the clothes, stand up straight, and keep the tape snug but not tight. Ask someone to help with the back if you can, because twisting round to read the tape gives you a false number every time.

• Bust: measure around the fullest part, keeping the tape level all the way round.
• Waist: find your natural waist, which is the narrowest point, usually just above the belly button. Don't suck in.
• Hips: measure around the fullest part of your bottom, roughly 20cm below the waist.
• Inside leg: from the top of your inner thigh to where you want the hem to sit, especially for trousers and jeans.

Write these numbers down in your phone. They are the reference point for every single purchase from now on, and they will save you an enormous amount of hassle.

Read the Size Chart, Then Read It Again

Every online shop should publish a size chart, but they hide in different places. Look for the words size guide or fit and measurements near the size selection or at the bottom of the product page. Don't assume it's the same as the last site you visited, even if it stocks similar brands.

Compare your measurements to the chart one at a time rather than looking for your usual number. If your bust points to a 22 and your hips point to a 24, you have a choice to make. For a fitted dress, go with the larger measurement and have it taken in at the waist. For a loose blouse, sizing down is usually safe. If the chart gives centimetres and you measured in inches, convert carefully. Two and a half centimetres to the inch, not two, and the difference matters over a 120cm hip.

Some retailers list garment measurements rather than body measurements. That means the tape measure laid flat across the actual item. Double the bust and waist numbers on the chart before you compare, or you will order something that fits a child. Look for wording like measured flat to know which you are reading.

Use Reviews Like a Fitting Room

Customer reviews are the closest thing to trying clothes on without leaving the sofa. Filter for reviewers who mention their height, their usual size and their shape. A review that says "true to size" from someone 5ft 2in with an hourglass figure tells you almost nothing if you are 5ft 10in and pear-shaped.

Search the review section for words like runs small, generous, short in the body or tight on the arms. Look at the photos customers upload, because these are unedited and show how fabric actually hangs. Pay attention to comments about stretch, lining and whether the material goes see-through when it is pulled across the bust or thigh. Reading ten reviews takes two minutes and can save you a fortnight of returns.

It also helps to notice patterns. If three people say the same dress gapes at the armhole, believe them.

Prioritise Free Returns and Clear Policies

Online shopping only works when you can send things back without losing money. Before you add anything to your basket, check the returns policy in full. What you want to see is free returns, or at least a prepaid label, plus a returns window of at least 28 days. Anything shorter is difficult to manage around work and life.

Check whether returns are accepted on sale items, because many shops exclude them. Find out if you get a refund or only a credit note, and whether you need to keep the original packaging. If a shop charges £4 to return and you are ordering three sizes to try, that adds up fast.

One practical trick is to order two sizes of the same item when you are unsure and the returns are free. Try both at home, keep the one that fits, send the other back. It costs nothing and removes the guesswork entirely.

Pay Attention to Fabric and Cut

The number on the label is only half the story. A size 22 in stiff, unforgiving cotton behaves completely differently from a size 22 in jersey with a bit of elastane. Read the fabric composition and think about what you need the garment to do.

• Stretch: anything with 3 to 5 per cent elastane will move with you and forgive a slightly off measurement.
• Structure: woven fabrics hold their shape but show every pull line, so fit matters more.
• Drape: viscose and modal skim the body beautifully; heavy polyester can cling in the wrong places.
• Lining: a lined skirt or dress sits smoother and avoids anything showing through.

Look at the cut too. Empire lines, wrap styles and A-line skirts tend to be more forgiving around the middle. Straight-cut shifts and boxy shapes can add bulk where you don't want it. None of this is about hiding anything. It is about choosing clothes that make you feel good the moment you put them on.

Build a System That Works for You

Keep a note on your phone with your measurements and the brands where you know your size. Add a short line about each, such as "size 20, generous in the bust, order a 22 in coats". Over a few months this becomes your personal size chart, far more reliable than anything a shop provides.

Buy from places with free returns, read the reviews properly, and trust your tape measure over the label. Do that and online shopping stops being a gamble. It becomes what it should be: a calm, private way to find clothes in your size that fit well and make you feel like yourself.