Are Cheap Insoles Worth It? When a Replacement Insole Helps

Replacement insoles are inexpensive compared with new shoes, which makes them tempting when a pair starts to feel flat or uncomfortable. Sometimes they are a great fix. Sometimes they are money spent on the wrong problem. Here is how to tell.

This guide covers general comfort. Insoles are not a treatment for medical conditions. If you have persistent foot, knee or back pain, see a podiatrist or doctor; they can advise whether a specific insole or custom orthotic is appropriate.

What the stock insole does

Most shoes come with a thin removable foam insole (sometimes called a sockliner). Its job is mainly comfort and a smooth surface for your foot. In many shoes, especially inexpensive ones, it is quite basic. Most of the shoe's cushioning comes from the midsole, not the insole. See midsole foams explained.

When a replacement insole can help

• The shoe fits well but feels flat. A cushioned insole can add a little softness.
• You want more arch contour. Insoles with a shaped arch can feel more supportive than a flat stock insole.
• Your heel slips slightly. A thicker insole can take up a little extra volume.
• The original insole is worn out but the rest of the shoe is in good condition.
• You want to move a favorite insole between pairs, such as work boots and casual shoes.

When it will not help

• The shoe is the wrong size. An insole cannot fix a shoe that is too short or too narrow, and a thicker insole makes a tight shoe tighter. See our measuring guide.
• The midsole is worn out. If the midsole has compressed or the outsole is worn through, a new insole only masks the problem. See when to replace running shoes.
• You have a medical condition. Get professional advice.

Types of insoles

Cushioned insoles are soft and add comfort. They tend to compress over time.

Supportive or structured insoles have a firmer shaped arch and a deep heel cup. Some people find them more comfortable for long periods on their feet; others find them uncomfortable at first.

Thin performance insoles add some structure without taking up much space, for shoes that are already a close fit.

Heat-moldable insoles can be shaped to your foot at home following the manufacturer's directions.

How to choose

1. Match the volume. If your shoe is already snug, choose a thin insole. If there is spare room, a thicker one is fine.
2. Match the arch. If you are not sure, start with a moderate arch rather than a very high one.
3. Match the use. Running, standing all day and hiking may suit different insoles. See shoes for standing all day.
4. Check the returns policy in case it does not suit you.

How to fit an insole

1. Remove the original insole.
2. Place the original on top of the new one, aligning the heels.
3. If the new insole is longer, trim the toe end to match, a little at a time, following any trim lines.
4. Insert it and check that it sits flat with no curling at the toe or edges.
5. Wear it around the house first and build up gradually, especially with firmer insoles.

Insole or new shoes? The cost comparison

If a shoe fits well, has a healthy midsole and outsole, and simply feels a bit flat or unsupportive, an insole is usually much cheaper than a new pair, and it can be moved to your next shoe. That improves your cost per wear.

If the midsole is compressed, the outsole is worn through, or the shoe does not fit, replace the shoe.

The bottom line

A replacement insole is worth it when the shoe fits and is structurally sound but needs more comfort, arch contour or a fresh surface. It cannot fix the wrong size or a worn-out midsole, and it is not a substitute for professional advice when you are in pain.