Quick Answer: Wide legs have more fabric, more swing and a hem that trails behind the heel, so the back edge contacts the ground repeatedly with every step. Add a hem cut for heels and worn with flats, and the wear rate multiplies. The fixes are hemming to the shoes you actually wear, adding hem tape or a kick tape to the inside back edge, and choosing a slightly shorter length for anything you walk in daily.

Hems do not fray from washing. They fray from the pavement.

And a wide leg puts several times more fabric against that pavement than a straight one.

Why does the back of the hem go first?

Because it trails. As you step forward, the back of the hem swings down and back, contacting the ground behind the heel.

Wide legs swing further, so the contact is heavier and more frequent than on a narrow trouser.

The heel of the shoe presses the fabric into the ground, which is what actually abrades it - the fabric is caught between shoe and pavement.

Rough pavement does the damage quickly, and city pavements are considerably rougher than they look.

Wet ground accelerates it, since wet fibres are weaker and dirt acts as an abrasive.

Which is why the wear is always at the back and never at the front, and why the front hem can look new while the back is finished.

What is the length actually meant to be?

Roughly one centimetre off the ground at the back, with the shoes you will actually wear.

The front should just break on the shoe, with a very slight fold, or sit clean with no fold at all for a sharper look.

Hemmed for heels and worn with flats is the single most common error and it adds several centimetres of trailing fabric.

Which means one pair of trousers realistically serves one shoe height, and that is worth accepting rather than fighting.

If you need both, hem for the flats and accept a slightly short break with heels, which reads far better than dragging.

And check the length standing on a hard floor, not carpet, since carpet lifts the hem by close to a centimetre.

What actually protects the hem?

Kick tape or hem tape sewn inside the back edge, which is a strip of hard-wearing ribbon that takes the abrasion instead of the fabric. It is standard on well-made trousers and absent from most.

A tailor can add it cheaply, and it is the single best intervention here.

A deeper hem allowance means it can be re-hemmed later, so check the allowance before buying - a two-centimetre hem cannot be rescued.

Rotate which trousers you wear in wet weather, since wet-weather wear is where most of the damage happens.

Brush dried mud off rather than rubbing it wet, which grinds grit into the weave.

And repair fraying early, because once the hem stitching goes the whole edge unravels quickly.

5 Wide-Leg Hem Mistakes

1. Hemming for heels and wearing them with flats. This is the most common and most damaging error. It adds several centimetres of trailing fabric and multiplies the contact with the ground on every step.

2. Checking the length on carpet. Carpet lifts the hem by nearly a centimetre, which is exactly the margin that matters. Check on a hard floor in the shoes you will wear.

3. Ignoring the hem allowance when buying. A generous allowance means the trousers can be re-hemmed once or twice over their life. A minimal one means the first fray is terminal, and it is easy to check by turning the hem out in a shop.

4. Washing damage in rather than brushing it off. Wet mud rubbed into a hem grinds grit into the weave and accelerates the abrasion. Let it dry, then brush.

5. Leaving fraying until it is obvious. Hem repairs are cheap and quick when the edge is intact and expensive when the stitching has gone and the fabric has unravelled. The window is a few weeks.

And the one worth building in from the start: asking for kick tape at the point of hemming. If you are paying for a hem anyway, adding a protective tape to the inside back edge costs very little more and roughly doubles the life of the hem.

FAQ: Wide-Leg Hem Questions, Answered

How long should wide-leg trousers be?

About a centimetre off the ground at the back with your usual shoes, breaking very slightly at the front.

What is kick tape?

A hard-wearing ribbon sewn inside the back hem edge that takes the abrasion instead of the fabric. It is standard on good trousers and absent from most.

Can frayed hems be repaired?

Yes, if caught early - the hem is turned up slightly and re-stitched. Once the fabric has unravelled significantly the trousers get shorter each time.

Should I have separate trousers for heels and flats?

Realistically one pair serves one shoe height. If you only own one, hem for flats.

How do I check the hem allowance before buying?

Turn the hem out and look. Anything under about four centimetres limits future alterations.

Does fabric type change the wear rate?

Yes. Loosely woven linen and soft viscose fray fastest; tightly woven wool and twill last longest.

TL;DR:

• Wide legs swing further and trail behind the heel, so the back hem is pressed into the pavement with every step.
• Hem to the shoes you actually wear - hemmed for heels and worn with flats is the main cause of fast wear.
• Ask for kick tape inside the back hem edge; it costs little and roughly doubles hem life.
• Check the length on a hard floor, not carpet, which lifts the hem by nearly a centimetre.
• Check hem allowance before buying, and repair fraying within weeks rather than months.

The washing machine is innocent. It is the pavement, several thousand times.