Where should I start if I want to make a small spreadsheet app?

Start by writing down the one thing you wish your current spreadsheet handled better. A complete spreadsheet means much more than a grid: formulas, editing, saving, copying, selection, keyboard behavior, and file compatibility all add up quickly. One focused feature is a project you can actually finish and learn from.

For a first prototype, make a small grid, maybe 10 by 10, where you can type plain text into cells. A basic web page with JavaScript is a straightforward way to experiment with the interface, even if your eventual goal is a desktop app.

Keep the cell data separate from how it is displayed. Then add one feature at a time: save and load, reference another cell, and do simple arithmetic. You’ll hit real programming problems without having to tackle a whole spreadsheet at once.

Learn the fundamentals first, then build a tiny version in stages. A command-line program that stores rows and columns and can calculate a few expressions is less exciting to look at, but it lets you focus on data and logic before adding a user interface.

Once that part makes sense, choose a desktop framework and connect the same logic to a grid. Try not to mix the calculations, stored values, and drawing code together. It makes changes much less painful.

If the main goal is making your work easier, you might not need to make a spreadsheet at all. A small script that automates the annoying step, cleans up data, or creates a report could solve the specific problem with a lot less work.

And if the goal is learning, that’s a perfectly good reason to make a toy spreadsheet. Just treat it as a learning project, not something that needs to match the features of a mature spreadsheet program.