House Flip Calculator

Work out the profit on a property flip after purchase, works, holding costs and selling costs.

freeworks offlinenothing uploaded
Input
Output

About house flip calculator

House Flip Calculator is one page doing one thing. No account, no settings to sync, no history building up somewhere.

The tool is a few kilobytes of JavaScript, not a service. That is why it can promise your data stays put and actually mean it.

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 150,000 purchase sold at 230,000 after a 4 month refurbishment
25,000 of works and 500 a month in holding costs while empty
Input
purchasePrice: 150000
refurbishmentCost: 25000
purchaseCosts: 6000
holdingMonths: 4
monthlyHoldingCost: 500
sellingPrice: 230000
sellingCostsPercent: 1.5
sellingLegalFees: 1200
Output
Total holding cost: 2000
Selling costs: 4650
Total costs: 187650
Profit: 42350
Profit margin percent: 18.41
Return on investment percent: 23.14

Questions

Does House Flip 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 House Flip 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.