Why I built KaufKompass (happy to answer questions)

Hey everyone, maker here.

I built KaufKompass after noticing that most mortgage/affordability calculators are made by banks or brokers, so they're optimized to show you what gets approved, not what's actually safe for your budget.

A few things I tried to get right:

• Closing costs are calculated per German state (Grunderwerbsteuer varies from 3.5% to 6.5% depending on where you buy)

• - The affordability check follows the same household-budget logic banks actually use, not a generic "33% of income" rule of thumb

• - It shows your remaining loan balance when your fixed-rate period (Zinsbindung) ends, since that's the number that quietly wrecks people's plans in year 10-15 and most tools never surface it

• - Everything runs client-side, nothing gets uploaded anywhere

It's available in German and English since a lot of expats buying property in Germany hit the same wall of German-only tools.

Would love feedback, especially if you've been through a real financing process and think something's missing or oversimplified.