One Swiss Knife in the exact shape of your life.

Tax Estimator

A private tax estimator in one HTML file on your machine: income in, estimate out, without an aggregator ever seeing a number.

Live · runs in your browser · no network

This is not a screenshot. It's the real tool, running right here: go on, put something in it.

Open the demo full-screen: /demos/tax-estimator.html

Forged into a knife, this tool ages with use: the blades you reach for wear soft, entries you tend keep their bloom, and the years travel with the file through every reforge.

Freelance money arrives feeling entirely yours, and some of it is only visiting. Tax Estimator is the modest place to keep a running sense of what the tax office will eventually want, so the bill arrives as an appointment rather than an ambush. It won't file anything for you — it just keeps you honest with yourself through the year.

KindTracker · keeps what you put in
CategoryFinance
Weight1
Manual:

Standing facts

In ten years

Whatever you put in stays inside the file itself. There is no account to lapse, no plan to be sunset, no migration e-mail with a deadline in it. A decade of tax estimator entries is a decade of your own handwriting, kept in a document you can back up like any other.

If Offline.Ltd closes tomorrow, nothing on your machine notices. That isn't a marketing promise; it's simply what a file is.

Getting your data out

Export to CSV from inside the tool and open it in anything: a spreadsheet, another app, a text editor. Or keep the HTML file: it is plain, readable, and inspectable; you can open it in a text editor and see your own rows sitting there. No export queue, no "we'll e-mail you a link within 48 hours", no format that only one vendor can read.

Copy the file to a USB stick, a NAS, a folder your devices already sync. It runs on Windows, macOS, Linux, Android and iOS, online or off, because a browser is the only thing it ever needed.

Questions people ask

01

What does the Tax Estimator actually do?

It helps you keep a rough, running estimate of the tax owed on what you earn, so you can set the right amount aside as you go. It's a self-honesty device, not a filing service.

02

Who is the Tax Estimator for?

Freelancers and side-giggers whose income arrives untaxed — anyone who has ever spent the tax money by accident and would rather not repeat the experience.

03

Is my income data safe in the Tax Estimator?

It never leaves your machine. The estimator is one HTML file running offline in your browser — no account, no upload, and certainly no line to any tax authority. The file and everything in it are yours.

Go deeper on Tax Estimator

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Fits your knife at weight 1. Nothing here is final, Knife follows Life. Reforging within your tier is free, forever. Add it, drop it, reforge it later; the file stays yours either way.

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