Repair vs Replace Calculator

Compare repairing against replacing an item by spreading each cost, plus its running cost, over its remaining life.

freeworks offlinenothing uploaded
Input
Output
—

About repair vs replace calculator

Repair vs Replace Calculator keeps its state in memory and nowhere else. That is why it forgets everything on reload, and why it cannot leak anything.

There is no account and no upload step. Whatever you paste lives in a variable until you close the tab, and then it does not.

You will find it under Property, alongside 12 other tools for the same sort of job.

Runs in this tab, so nothing you type is uploaded.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

A boiler with 4 years of life left in it against a new one rated for 15
The old boiler costs more to run each year
Input
repairCost: 800
repairRemainingLifeYears: 4
repairAnnualRunningCost: 150
replaceCost: 3000
replaceLifeYears: 15
replaceAnnualRunningCost: 40
Output
Repair annualised cost: 350
Replace annualised cost: 240
Cheaper option: replace
Annual difference: 110

Questions

Does Repair vs Replace Calculator work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use Repair vs Replace Calculator on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.