The price on the tag is not the price

A 300 coat worn a hundred times costs less per outing than a 30 jumper worn three times and then forgotten. That is the idea of cost per wear: dividing what an item really costs you by the number of times you use it. It applies to clothes, but also to running shoes, tools, bags, appliances, memberships and anything you buy to use over time.

This calculator adds two items the price tag does not show: how much you get back by reselling the item at the end, and how much you spend caring for it each time you use it, from washing and dry cleaning to repairs, refills or consumables. It works in any currency.

How the calculation works

You enter the purchase price P, how many times a month you use it u, for how many months M, the care cost per use c and the resale value at the end of its life R.

• Total uses: N = u × M.
• Total cost of ownership: (P − R) + c × N, that is what you lose on the price plus all the care.
• Cost per use: the total cost divided by N, which equals (P − R) / N + c.
• Care share: the part of the total cost due to upkeep.

The verdict is based on the care share: a percentage that depends neither on the currency nor on the price, and that tells you which of the two levers, using it more or spending less to maintain it, really matters in your case.

Why using it more lowers the cost

The purchase part is divided by the number of uses: doubling the uses halves it. The table shows an item costing 100 with no care cost and no resale.

The first few dozen uses do almost all the work: from 10 to 30 uses the cost falls by two thirds, from 100 to 200 by only 50 cents. That is why one of the most quoted rules in sustainable fashion, the #30wears campaign launched by Livia Firth, asks you to buy a garment only if you are sure you will wear it at least thirty times.

Care is the part that does not divide

The care cost per use stays the same however many times you use the item: it is a floor below which the cost per use cannot fall. The table shows an item costing 100 used a hundred times, with rising care costs.

Once care exceeds half the total cost, the purchase price becomes the smaller item. A dry-clean-only garment, a capsule coffee machine, a printer with expensive cartridges: in all these cases it pays to look first at what each use costs and only then at the price tag.

The quality advantage melts with care

"Buy less but buy better" is common advice, and often it is right. But its advantage depends on care. Let us compare garment A costing 25 that lasts 30 uses with garment B costing 90 that lasts 150, with the same care cost for both.

With no care, the quality garment costs 28% less per use. With a dry-clean bill of 5 per use the advantage shrinks to 4%: the price gap has been diluted in a cost both garments pay equally. Quality remains a good choice for durability, comfort and the environment, but its financial advantage is large only when care is cheap.

The care crossover point

The calculator also shows after how many uses the accumulated care exceeds what you lost on the purchase price: N* = (P − R) / c. Beyond that threshold, each new use costs mainly in upkeep. For a 120 garment resold at 20, with 30 cents of washing per use, the crossover comes after about 333 uses; for a 20 T-shirt with 80 cents of care, after just 25.

Resale value

Reselling an item at the end of its use reduces the purchase part, because what you get back was never really spent. Bags, watches, sports equipment, technical or designer clothing and musical instruments often keep part of their value on the second-hand market; fast fashion almost never does. If you do not plan to resell, enter zero.

The four bands of the verdict

• Care below 20%: you mostly pay for the purchase, and the lever is to use it more.
• 20% to 40%: the purchase still weighs more, but the cost per use soon stops falling.
• 40% to 60%: care and purchase are level.
• Above 60%: care is the real price, and it pays to cut the cost of each use.

If total uses are fewer than thirty, the verdict says so: it is the most quoted threshold for a purchase that has been well used.

Estimating uses and care

For a garment, what counts is how often you wear it in a season and how many seasons it lasts; running shoes are often measured in kilometres or miles, which convert into runs. The care cost of a machine wash is estimated by dividing the water, energy and detergent of one cycle by the items washed together; a dry clean or a repair is divided by the uses between one service and the next. A reasonable estimate is enough: the calculator is there to show the order of magnitude.

Limits of the calculator

The model uses a constant average care cost and a regular number of uses. It does not account for the value of the time spent on care, environmental impact, the pleasure of use or the cost of having to replace sooner an item that breaks. Cost per wear is a tool for comparing purchases, not a judgement on what is worth owning.

Frequently asked questions

What is cost per wear?

It is what an item costs you each time you use it: the total cost of ownership, that is price minus resale plus all the care, divided by the number of uses.

How do you calculate cost per wear?

Divide what you lose on the price, that is price minus resale value, by the number of uses, and add the care cost of each use, such as a wash or a refill.

What is the 30 wears rule?

It is the rule popularised by Livia Firth's #30wears campaign: buy a garment only if you are sure you will wear it at least thirty times. The calculator flags when uses are fewer than thirty.

Is buying quality always worth it?

Often, but the financial advantage depends on care. If each use needs an expensive clean, the price gap gets diluted and the quality item's saving per use shrinks considerably.

What should I enter as the care cost?

What you spend on average for each use: your share of a machine wash, a dry clean divided by the uses between cleans, repairs, refills or consumables.

Why does the care share matter?

Because it tells you which lever works. If care weighs little, using the item more cuts the cost a lot; if it is more than half the total, using it more changes little and it pays to cut the cost of each use.

What is the care crossover point?

The number of uses beyond which the accumulated care exceeds what you lost on the purchase price. You get it by dividing price minus resale by the care cost of one use.

Should I enter a resale value?

Only if you really plan to resell the item. Bags, watches, sports equipment and instruments often keep value; fast fashion almost never does. If you will not resell, enter zero.

Does it only work for clothes?

No. It works for shoes, tools, appliances, coffee machines, bicycles, memberships and anything you use repeatedly over time.

Does it work in any currency?

Yes. Enter price, care and resale in the same currency and the results are in the same unit; the verdict is based on a percentage that does not depend on the currency.

How do I estimate the number of uses?

Count how many times you use it in a typical month and for how many months you expect to keep it. For seasonal clothing, think about the months you actually wear it.

Does the calculator account for environmental impact?

No, it measures only the financial cost. Using what you own for a long time is, however, also one of the most effective ways to reduce the impact of what you consume.