Qalqlet is live: source-backed financial calculators for the UK and Netherlands
I’ve just launched Qalqlet, a free financial calculator platform for the UK and the Netherlands.
Most financial calculators provide a number and leave users to work out what it means. Qalqlet is designed around the full decision journey.
For example:
• Salary → tax → pension → take-home pay
• Mortgage → affordability → household budget
• UK job offer → Netherlands offer → local cost comparison
The platform currently includes salary, tax, mortgage, pension, benefits, business and household tools.
What makes it different:
• No sign-up required
• Calculations backed by official sources
• Visible assumptions and applicable tax years
• Review dates for important financial rules
• Separate UK and Netherlands calculation systems
• A UK–Netherlands salary and living-cost comparison
Qalqlet is bootstrapped and free to use.
UK calculators:
Netherlands calculators:
UK–Netherlands comparison:
I’d particularly appreciate feedback on three things:
1. Do the visible sources and assumptions make the results feel more trustworthy?
2. Which calculator would you use first?
3. Which country should Qalqlet support next?
The visible assumptions and review dates are a thoughtful detail.
With financial calculators, the number itself is only part of what a user has to decide whether to trust.
Exactly. A number can be mathematically correct and still be misleading if the user doesn’t know which assumptions produced it.
The goal isn’t to pretend we can model every personal situation perfectly. It’s to make the boundaries visible enough that users can judge whether the estimate is useful for their decision.
Exactly. Making uncertainty visible is often what makes a tool more trustworthy, especially when the output influences real decisions.
Absolutely. Uncertainty shouldn’t be hidden in a disclaimer at the bottom of the page — it should be part of the product experience.
A useful estimate is not one that pretends to be perfect, but one that makes its assumptions and limits clear enough for someone to use it responsibly.
Exactly. In decision tools, transparency around limitations can be as important as the calculation itself.