How to buy jeans online that actually fit

Why the size label is not enough

A W30 or a size 12 tells you roughly where to start, but jeans vary between makers, styles and years. Two pairs with the same label can differ by several centimetres at the waist, and more at the thigh. Our guide to why size labels differ explains why. The fix is simple: measure.

Step 1: measure your best-fitting pair

Choose the jeans that fit you best, ideally in a similar style and fabric to what you want to buy. Lay them flat on a table, button and zip done up, and smooth out the creases.

• Waist: straight across the top of the waistband, then double it.
• Front rise: from the crotch seam up to the top of the waistband at the front. This tells you whether jeans sit low, mid or high on you.
• Hip: straight across at the widest point, usually just below the bottom of the fly, then double it.
• Thigh: across one leg, just below the crotch, then double it.
• Inside leg: from the crotch seam down the inside seam to the hem.
• Leg opening: straight across the hem, then double it.

Write them down. These numbers become your benchmark for every pair you buy. Our guide to measuring clothes covers each one.

Step 2: know which numbers matter most

• Waist and hip decide whether they will do up and sit comfortably.
• Rise decides where they sit, and whether they gape at the back.
• Thigh is often the one that catches people out, especially on slim styles.
• Inside leg decides the length. Jeans can be shortened, but not lengthened much.
• Leg opening tells you the shape: narrow for skinny, wider for straight, bootcut or wide leg.

Step 3: allow for stretch

Check the composition label.

• 100% cotton (rigid) denim has little give. The waist and hip should be within a centimetre or two of your benchmark pair, or a little bigger.
• Stretch denim with some elastane can measure slightly smaller than your benchmark and still fit, and it will ease a little with wear.
• Very stretchy jeans can measure noticeably smaller. Compare them with a pair of similar stretch, if you have one.

Raw or unwashed denim can shrink when first washed, so check the listing or ask the seller whether it has been washed.

Step 4: think about style

The same measurements fit differently in different cuts.

• Skinny and slim fit close through the thigh and calf.
• Straight runs the same width from the knee down.
• Bootcut and flared widen from the knee.
• Wide leg and relaxed are loose throughout.
• Tapered styles are usually roomier at the hip and narrower at the ankle.

If you are trying a new style, compare the waist, rise and hip with your benchmark, and expect the thigh and leg opening to differ.

Step 5: ask before you buy

On Rewear, measurements are optional, so not every listing has them. If any are missing, tap Message the seller and ask. A message such as "Could you measure the waist, rise and inside leg, laid flat?" is quick to answer. While you are at it, ask for a photo of the crotch and inner thighs held up to the light, since that is where denim wears first.

You can also save your measurements in your Rewear profile, and we use them to tell you how a measured piece is likely to fit you.

Common mistakes

• Buying by label size alone.
• Forgetting the rise. Two pairs with the same waist can sit very differently.
• Ignoring the thigh on slim and skinny styles.
• Comparing stretch with rigid. A rigid pair needs more room than a stretch one.
• Forgetting to double the flat measurements before comparing with your body.

When they arrive

Try them on as soon as they arrive, with the shoes you would wear them with. Rigid denim may feel snug at first and soften with wear. If they are not as described, for example a different size on the label or damage that was not mentioned, message the seller through the app and open a problem report on the order within 14 days of delivery. A fit that matches the listed measurements is not the same as a listing being wrong, so measure first. Our Terms explain the rest.

Looking after them

Wash jeans less often, inside out and cool, and dry them away from direct heat to keep their fit. Our guide to caring for denim explains more, and our guide to spotting good quality denim explains what to look for in the fabric and stitching.

The short version

Measure your best-fitting pair, compare waist, rise, hip, thigh and inside leg in cm, and allow for stretch and style. Ask the seller for any missing measurements, and check the crotch and thighs for wear before you buy.