About IfSketch
IfSketch is an independent interactive website built to make curious questions easier to explore. It combines mathematics, scientific reasoning, interactive experimentation and everyday calculations — without asking anyone to create an account.
What you can do here
Discover a question, change the assumptions, watch the result move, and read why. Some experiments are planetary thought experiments. Some are a standing order and a number of years. Both belong: half the site is “that's fascinating”, half is “that's actually useful”.
What this is not
It is not a blog farm, a quiz, a set of fake widgets, financial advice, medical advice or a research partnership with anyone. There is no login, no newsletter wall and no requirement to talk to an AI model. The calculations run in your browser from published formulae and the numbers you type.
How to trust a number
Every experiment states its method, its assumptions and, where a fact is used, a source. If a scenario is physically impossible, the page says so. If a savings rate is an illustration, it is not labelled as a forecast. When the model is a sketch, the sketch is labelled.