I’ll build a simulation tool here. Until I complete it you should check out my Google Sheet that can run the numbers for now. For now, you will need to make a copy of the sheet to input your own values.

You fill in your inputs in Column B and the sheet will try to calculate some outputs on suggested equivalent rent levels in column E through G. The sheet suggests some values in Column C – some are based on my general intuition or research; some are based on calculations on the input fields in Column B. All the final values are calculated from the Column B inputs though so if you lower your down payment from 20% the sheet will calculate a suggested bank loan for you in Column C but you’ll need to note it in Column B before the changes take effect.

A hidden assumption in the sheet is that all the interest paid is within the 100,000 kr progression limit for tax deductions for a couple or 50,000 kr for a person filing individually. I’ll build a proper amortization table at some point to better capture outliers, but even a 4 million kr property at 2.5% will stay within this limit for a couple. Also, the deduction is just lowered a bit after 100,000 kr but is not completely removed so the calculation error is not too big.

I’d appreciate any input you have! Either comment here on the page, at my post here, or reach out to me by email. Don’t judge me by the ugliness of it all though 😉

Hi,

Great spreadsheet! One question though, I see ‘Expected total costs’ for buying does not take appreciation into consideration. Is this intended?

Hi AKN

Great catch. Definitely not intended – I corrected it right away and it changes the conclusions especially if you count on high appreciation. It’s an old sheet and I actually have a newer version where inflation is adjustable too, but I’m unsure if it ever got finished so I don’t really want to reroute the links.

Great google sheet! Very useful and informative, especially for a foreigner moving here looking to buy. But I found , what I think a re a few bugs in the formula for the house value. Negative interest rates, and house depreciation, do not yield sensible values, unless I’m much mistaken in my understanding of their effect.

The interest and principle payment appear to be calculated correctly but then I’m not so sure.

Hi

Thanks for commenting. I just took a quick look and negative appreciation and negative interest seems to work – I might be wrong though. Also I haven’t ever heard of negative interest on actual mortgages.

I have an F3 mortgage with a negative interest rate. As far as I’ve understood it, my lender (TotalKredit) sets my interest to 0% and have then recently decided to pay back some of the negative interest to its customers via KundeKroner; https://www.totalkredit.dk/boliglan/kundekroner/

I’ve noticed that your spreadsheet is named “_old version”. Do you have the link for a new version?

Hi M

I saw the newer version too the other day, but I made it so far back that I’m not sure it’s validated yet or if there’s actually anything new in it. It’s here but proceed with caution 🙂

https://docs.google.com/spreadsheets/d/1ZbwWc63foALaEWL4I_zvKh2tXKssTeIA6QgpZNar0vY/edit#gid=0

Best regards