Cost Per Use: The Simple Formula for Deciding What Is Really Worth Buying

The price tag tells you what something costs today. It does not tell you what it will cost you over the months and years you own it. A cheap pair of shoes that falls apart after a season can cost more than a pricier pair that lasts five years. A bargain printer with expensive ink can cost far more than a slightly dearer model with cheap cartridges. And an exercise bike used twice is an expensive coat rack.

Cost per use is a simple way to see the real value of a purchase. It helps you decide when it is worth paying more, when the cheaper option is genuinely better, and when it is best not to buy at all.

The basic formula

Cost per use = total cost ÷ number of times you use it

For example:

• A coat costing 150 that you wear 100 times a winter for three winters (300 wears) costs 0.50 per wear.
• A coat costing 50 that you wear 100 times before it wears out (100 wears) also costs 0.50 per wear — but you will need to replace it, and it may keep you less warm and dry.
• A dress costing 80 worn twice costs 40 per wear.

The numbers make the trade-off visible: it is not the price alone, but the price relative to how much use you get.

Include the total cost of ownership

For many items, the purchase price is only part of the cost. Total cost of ownership includes everything you will spend while you own something:

• Purchase price, including delivery and installation.
• Running costs: electricity, fuel, water, ink, filters, batteries, subscriptions.
• Maintenance and repairs: servicing, spare parts, cleaning products.
• Accessories you need to make it useful.
• Disposal costs, if any.
• Minus resale value, if you can sell it later.

So a more complete formula is:

Cost per use = (purchase price + running costs + maintenance − resale value) ÷ number of uses

Examples

Printers

A low-cost printer may use expensive ink cartridges that run out quickly, while a more expensive model with refillable tanks or high-yield cartridges may cost much less per page. Calculate the cost per page from the price and stated page yield of the cartridges, then multiply by how many pages you print each year.

If you print very rarely, the cheapest option might be not to own a printer at all — using a library, print shop or workplace printer when needed.

Appliances

Two washing machines may differ in price but also in energy and water use. Over a machine's working life, running costs can add up to a significant sum, so an efficient model can be cheaper overall even if it costs more to buy. Energy labels help you compare.

Shoes and clothing

Well-made shoes that can be resoled, or a coat with sturdy stitching and durable fabric, may last many times longer than cheaper alternatives. But fashion items you will only wear a few times rarely justify a high price, however good the quality.

Tools and equipment

A cordless drill used regularly over many years has a very low cost per use. A specialist tool needed once — a tile cutter or carpet cleaner — usually has a very high cost per use if bought, making renting or borrowing a better option.

Kitchen gadgets

A good chef's knife used every day for a decade is excellent value. A single-purpose gadget used twice a year — an elaborate spiraliser, waffle maker or bread machine you rarely use — may not be, however tempting the price.

When paying more saves money

Spending more upfront tends to pay off when:

• You will use the item often, such as daily clothing, shoes, kitchen knives, pans, mattresses, office chairs and work tools.
• Durability varies a lot between cheap and better-quality versions.
• Running costs are significant, as with appliances, vehicles and printers.
• Repairs are possible with better-quality items (shoes that can be resoled, appliances with available spare parts).
• Failure is costly or unsafe, such as with tyres, brakes, electrical items and child safety equipment.
• Resale value is strong, as for some branded tools, furniture, instruments and bikes.

When the cheaper option is smarter

Paying less is often the better choice when:

• You will use the item rarely.
• You are trying out a new hobby and are not sure you will continue. Start with second-hand or budget equipment and upgrade if you stay interested.
• The item will be outgrown quickly, such as children's clothes and shoes (though safety items should still meet standards).
• The item is likely to be lost or damaged, such as umbrellas, sunglasses and phone cables.
• There is little quality difference between brands, as with many basic groceries, cleaning products and medicines with the same active ingredients.
• Technology changes quickly and expensive features may be outdated soon.

Brand name versus quality

A higher price does not always mean better quality. Some expensive products cost more because of marketing and brand image rather than materials and construction. To judge quality:

• Look at materials and construction — stitching, joints, thickness, hardware.
• Read independent reviews, particularly long-term reviews that mention durability.
• Check warranties. A long warranty suggests the manufacturer expects the product to last.
• Look for repairability: spare parts, replaceable batteries and service networks.
• Compare specifications rather than brand names.

Estimating uses honestly

The weakest part of the calculation is often the number of uses. People are optimistic about how often they will use new purchases — the exercise equipment, the hobby kit, the special-occasion outfit.

To estimate more realistically:

• Look at your past behaviour. How often have you used similar items?
• Think about where it will be stored. Items that are hard to reach get used less.
• Consider your schedule. Will you really have time to use it?
• Count only realistic uses — ideally, uses you can already picture in your calendar.

If you are unsure, borrowing, renting or buying second-hand first is a low-risk way to test.

Using cost per use on everyday decisions

Coffee and lunches

Daily purchases can have a high annual cost. Compare a takeaway coffee with a home-made one, including the cost of a decent reusable cup, the coffee itself and equipment. The goal is not to give up treats, but to make conscious choices about which ones are worth their cost per day.

Subscriptions

Divide a subscription's monthly fee by the number of times you use it each month. A gym membership used twelve times a month may be excellent value; one used once a month may be very expensive per visit compared with pay-as-you-go options. Our subscription audit guide explains how to review these.

Cars and transport

The cost per kilometre or mile of owning a car includes purchase or finance costs, depreciation, insurance, tax, fuel, servicing, repairs, parking and tyres. Comparing this with public transport, cycling, car clubs or occasional taxis can reveal surprising differences, especially for households with a second car that is rarely used.

A worked comparison

Imagine choosing between two vacuum cleaners:

• Model A costs 80, uses disposable bags at 15 a year, and is expected to last about four years.
• Model B costs 180, is bagless with a washable filter, has a longer warranty and is expected to last about eight years.

Over eight years, you would probably buy Model A twice (160) and spend about 120 on bags, a total of around 280. Model B costs 180 plus perhaps a replacement filter or two — say 200 in total. If you vacuum twice a week, that is roughly 830 uses over eight years: about 0.34 per use for Model A versus 0.24 for Model B. The dearer machine is cheaper to own, provided its expected lifespan is realistic — which is where reviews, warranties and repairability come in.

The figures are illustrative, but the method works for any comparison. Write down the realistic lifespan, running costs and uses for each option, and the answer is often clearer than the price tags suggest.

Renting, borrowing and sharing

Cost per use also shows when not owning something is the cheapest choice. For items used only occasionally — carpet cleaners, pressure washers, camping equipment, party supplies, specialist tools and even cars — renting by the day or borrowing from friends, neighbours, tool libraries or sharing schemes can deliver the same benefit at a fraction of the cost of buying. Sharing ownership with family or neighbours is another option for things such as lawnmowers, ladders and trailers.

A simple decision checklist

Before a significant purchase, ask:

1. How many times will I realistically use it?
2. What will it cost to run and maintain?
3. How long will it last?
4. Can it be repaired?
5. What will it be worth when I no longer need it?
6. Could I borrow, rent or buy it second-hand instead?
7. What is the cost per use of the cheaper and dearer options?

Avoiding the trap of "investment" spending

Cost per use can also be misused to justify expensive purchases: "It's an investment piece; I'll wear it forever." Be honest with yourself. The formula only works if the uses actually happen. A good test is to wait a few days before buying anything expensive. If you still want it and can clearly picture regular use, the cost per use is more likely to be real.

The bottom line

Cost per use changes how you see prices. By dividing the total cost of owning something by the number of times you will realistically use it, you can see when quality is worth paying for, when cheaper options make sense, and when borrowing or renting is the best choice of all. Applied consistently, it leads to fewer, better purchases — and less money wasted on things that sit unused.