Wear and tear – definition and meaning

Wear and tear is the damage that happens to something when it is used ordinarily (properly) over a period of time. Wear and tear may refer to assets – when they gradually deteriorate from use, age, and/or weathering.

The term is commonly used in business, real estate (especially property rental), taxation, and accounting.

It is the normal and expected deterioration in the quality of physical items that happens over time.

Wear and tear, as a legal term, is used to express the notion that architecture, equipment, infrastructure, and products deteriorate (depreciate) over time.


When a manufacturer uses the term ‘wear and tear’ in a warranty contract, it is referring to the normal deterioration of a product after typical and/or proper usage. If your dog chews up one of your shoes, that is not considered normal wear and tear.


Wear and tear in warranties

The term is used in a legal context for warranty contracts from manufacturers, which typically state that damage from wear and tear will not be covered.

It is a type of depreciation which is assumed to happen even when something is used with care and proper maintenance.

For example, a pair of shoes will gradually deteriorate if you use them regularly. The wear and tear is impossible to prevent if the shoes are used for their designed task.

Any attempt to reduce the shoes’ wear and tear to zero will impede their functionality.

At the same time, the normal use of the shoes will not destroy them beyond repair during a reasonable life cycle.

Second law of Thermodynamics

According to the Second Law of Thermodynamics – a principle of physics – the total entropy of an isolated system always increases over time.

Put simply, everything tends to move from a state of order to a state of disorder – it is an irreversible process.

The principle indicates that nothing can be designed and constructed to last forever – it is impossible to avoid wear and tear.

Even software and data undergo a similar process of gradual deterioration, i.e. wear and tear. In the world of IT (information technology), this is known as software entropy and data rot.

Is aging a form of wear a tear?

All humans, animals, and plants gradually deteriorate as we get old. Is this a form of wear and tear?

In biology, the damage or error theory states that cells and tissues have vital parts that wear out, resulting in aging. Just like the components in a car or any machine, parts of the body wear out over time from repeated use, killing them and then the body.

The wear and tear theory of aging was first put forward by Dr. August Weismann (1834-1914), a German evolutionary biologist, in 1882.

Scientists continue arguing about the mysteries of aging. Perhaps there is a genetic switch that is turned on (or off) after a certain period, or how long we last depends on our metabolic rate. Maybe aging is the result of a combination of effects, including wear and tear.

In an article published in Aging and Disease in 2010, titled Modern Biologial Theories of Aging, Kunlin Jin, Adjunct Professor at the Buck Institute for Research on Aging, wrote:

“Overall, while multiple theories of aging have been proposed, currently there is no consensus on this issue. Many of the proposed theories interact with each other in a complex way.”

“By understanding and testing the existing and new aging theories, it may be possible to promote successful aging as well as to enhance the lifespan of mankind.”