Cost per use calculator
Before you buy something you will use a few times a year, work out what each use will cost. Put in the price, what it takes to keep running, what it will sell for and how often you will honestly use it. The calculator sets renting, buying alone and sharing next to each other and tells you how many uses it takes for owning to pay for itself.
It opens on the pressure washer from our cost per use guide. Change any number and the results update as you type.
Rent it each time
The rental price, every use.
- Over the whole time
- $1,040
- Per year
- $130
Buy it alone
Price plus running costs, less what it sells for.
- Over the whole time
- $370
- Per year
- $46.25
Share it 4 ways
Your part of the same cost, with every use still yours.
- Over the whole time
- $92.50
- Per year
- $11.56
Buying costs less than renting. Owning pays for itself on use number 6, and you expect 16 uses.
The example, worked through
The assumptions: a pressure washer that costs $350, with $60 of detergent, pump oil and winterizing over eight years, sold for $40 at the end. It comes out twice a year, once for the driveway in spring and once for the deck in fall. A day's rental is $65, and four households on the street would each use it about as often.
- Per use if you buy it alone
- $23.13
- Where owning starts to beat renting
- 6 uses
- Per use split four ways
- $5.78
All in, the washer costs $370 and gets used 16 times, so each use is $23.13. Renting 16 times would come to $1,040. Buying wins, and it wins early: $370 divided by the $65 rental is 5.7, so the sixth use is the one that puts owning ahead. At two uses a year that is the fall of year three.
Now change one number at a time. Drop to one use a year, which is where a lot of washers end up, and each use costs $46.25. Owning still comes out ahead of renting, but not until the sixth year. Or keep two uses a year and buy the $700 model: $45 a use, and it takes 12 uses, six years, before it has paid for itself.
Then set households to four. Each one pays $92.50 over the eight years and still gets its two uses a year, which is $5.78 a use. The washer is out on 8 days a year instead of 2 and spends the other 357 in one garage instead of four.
Getting the inputs right
The price is the easy part. The other numbers are where the sum goes wrong, nearly always in the direction that makes buying look better than it is.
- Uses a year. Count the times you needed one in the last twelve months and use that. If you have never owned one, take your guess and halve it.
- Running costs. Add the bills that arrive whether you use it or not: insurance, storage, registration, a yearly service. For a trailer or a jet ski these are larger than the fuel. Our jet ski cost breakdown shows how much of the total they are.
- Resale. Look up what used ones the same age are listed for, not what you hope to get. For most household tools the honest figure is small.
- Rental price. Use the day rate if a job takes you most of a day, and remember the trip there and back is part of what renting costs you.
If the sharing column wins
Splitting the cost is simple arithmetic. Keeping it fair afterwards is a question of who has the thing on which Saturday. On a small street a printed sign-out sheet on the garage wall can be enough, and by December it doubles as the real count of uses for next year's sum. When two households start wanting the same weekends, put it on a calendar. AllDibs gives each household a small budget of weekend days and turns away a booking that overlaps another, so nobody holds every dry Saturday in May. See how tool sharing works.
Questions about cost per use
What is cost per use?+
It is what one use of a thing costs you once everything is counted: the price, what it takes to keep it running, and what you get back when you sell it, divided by the number of times you use it before it goes. A $350 pressure washer used 16 times is about $23 a use. The same washer used 4 times before it seizes up in the shed is over $85 a use, which is more than renting one.
What is the cost per use formula?+
Price plus running costs, minus resale value, divided by total uses. Total uses is uses a year times the years you keep it. Written out for the example on this page: $350 plus $60, minus $40, is $370. Two uses a year for eight years is 16. $370 divided by 16 is $23.13.
What counts as one use?+
One occasion you would otherwise have rented or borrowed it for. A Saturday spent washing the driveway, the deck and the car is one use, not three, because one day's rental would have covered all of it. Counting this way is what makes the comparison with the rental price fair. For something you use for minutes at a time, like a drill, count the jobs.
What is a good cost per use?+
There is no single figure, so compare it with the rental price. If owning costs you less per use than renting, buying is sound. If it costs more than about half a day's rental, the rental counter is close to beating you once storage and upkeep are added, and that is the range where splitting it with neighbors pays off most. Under a couple of dollars a use, stop doing sums and buy it.
Is cost per wear the same calculation?+
Yes, with wears in place of uses. A $180 coat worn 20 times a winter for three winters is 60 wears, so $3 a wear. A $60 dress worn twice is $30 a wear. To use this calculator for clothes, put the cost of cleaning and repairs in running costs, set the rental price to 0 unless you really would rent it, and set households to 1.
Does sharing mean I get to use it less?+
Not for things that sit idle most of the year. Four households that each need a pressure washer twice a year want it on 8 days out of 365, and those days rarely collide. It stops working when everyone needs the thing at the same moment, which is the trouble with a shared snow blower: the whole street wants it the morning after the storm.
Bought it together? Book it together
Add the thing, send one invite link, and everyone can see when it is free. The first 5 items cost nothing and there is no card to enter.
Put it on AllDibs, free