A price tag tells you what something costs on the day you buy it. Cost per use tells you what it costs each time you actually use it. This calculator takes the purchase price, subtracts what you expect to get back when you sell it, and spreads the rest over the uses you expect to get.
How the calculation works
The calculator starts with the net cost: the purchase price minus the expected resale value. If you expect to sell a laptop for 300 after paying 1,500 for it, the part you actually spend is 1,200. Resale value cannot be higher than the purchase price in this calculator.
You can then count uses in one of two ways:
- Enter total number of uses. Use this when you can count uses directly, such as a kitchen appliance you expect to use about 160 times. The result is the net cost divided by that number of uses.
- Estimate from years and weekly use. Use this when the item is part of a routine. You enter how many years you expect to keep it, how many days a week you use it and how many hours you use it on a typical day.
In plain words, the schedule method works like this:
- Calendar days of ownership = years × 365
- Use days = calendar days × days used per week ÷ 7
- Cost per calendar day = net cost ÷ calendar days
- Cost per day used = net cost ÷ use days
- Cost per hour of use = net cost ÷ (use days × hours per use day)
The headline result in schedule mode is the cost per calendar day of ownership. That is what owning the item costs whether you touch it or not. The two smaller figures show the cost for each day you actually use it and for each hour of use.
Worked examples
Example 1 – a laptop used every day. Purchase price 1,500, no resale value, kept for 3 years, used 7 days a week for 5 hours a day.
Calendar days = 3 × 365 = 1,095. Because it is used every day, use days are also 1,095. Use hours = 1,095 × 5 = 5,475.
Cost per calendar day = 1,500 ÷ 1,095 ≈ 1.37. Cost per day used ≈ 1.37. Cost per hour = 1,500 ÷ 5,475 ≈ 0.27.
Example 2 – a bike used at weekends. Purchase price 900, expected resale value 200, kept for 4 years, used 2 days a week for 1.5 hours.
Net cost = 900 − 200 = 700. Calendar days = 4 × 365 = 1,460. Use days = 1,460 × 2 ÷ 7 ≈ 417. Use hours ≈ 417.14 × 1.5 ≈ 626.
Cost per calendar day = 700 ÷ 1,460 ≈ 0.48. Cost per day used = 700 ÷ 417.14 ≈ 1.68. Cost per hour = 700 ÷ 625.71 ≈ 1.12.
Example 3 – a stand mixer counted by uses. Purchase price 400, no resale value, 160 expected uses entered directly.
Cost per use = 400 ÷ 160 = 2.50. In this mode the calculator shows only the cost per use, because there is no time period to divide by.
What the result does and does not include
The calculator covers the purchase price and resale value only. Running costs such as electricity, ink, servicing or insurance are not part of this calculation. If those matter for your decision, the compare cost per use calculator adds annual maintenance, and the cost per wear calculator adds cleaning, repairs and fees for clothing.
The result describes the scenario you enter. It is not a recommendation to buy, and it does not predict how long the item will really last.
A note on the numbers
The two usage modes often tell different stories about the same purchase. In the bike example, the cost per calendar day is under half a unit, while the cost for each day it is actually ridden is more than three times higher. Neither number is wrong. One describes the cost of having the bike available, the other the cost of the rides themselves. Which one feels more useful depends on why you are buying it, and that part is your call.