Web App
kakeru
Multiply your thinking — a calculator that connects and visualizes.
A new kind of calculator. You turn formulas into cards, connect them to each other, and visualize the results on the spot. "People × unit price," "rate × principal" — you build the kind of math you actually think through, all on a single board.
What you can do
- Connect calculation cards — reference one card's result from another formula; change it and everything recalculates.
- Visualize instantly — bar & pie charts, progress gauges, deltas, stacked bars, waterfalls, scatter plots.
- Function plots f(x) — type a formula to draw the curve; drive its coefficients from other cards.
- What-if with sliders — drag a value and the connected charts follow in real time.
- Save & share — share a board by URL or image, or start from a template.
Where it fits
- Money — budgets, trip costs, mortgages, investment simulations.
- Math — visualize functions, areas, and ratios.
- Science — unit math, physical quantities, correlation of experimental data.
- Life planning — long-term simulations like education funds and retirement.
About the name
The name is a Japanese verb, kakeru, that carries several meanings at once — and the app leans on all of them:
- 掛ける — to multiply. The calculator underneath it all.
- 書ける — to write. You write the formulas, and the reasoning stays written on the board.
- 架ける — to build a bridge. Between cards, and between people: a finished board travels as a URL or an image. With no server in the middle, it goes from one person straight to another.
Privacy
There is no server behind kakeru. Your data is stored only in your browser, on your device, and is never uploaded anywhere. Use it with confidence even for household budgets and personal numbers.
Running in the browser alone is kakeru's own choice, not a rule codinganyway applies to everything it builds.