Free Tools

What this site is

SJ AI Studio is a set of calculators, converters and reference guides that run entirely in your browser. There is no sign-up, nothing to install, and no value you type is sent to a server — every calculation happens on your own device.

The tools cover the questions that are easy to ask and annoying to answer: what a property acquisition tax comes to, how much stain a fence will take, what a belt size means in another country’s numbering, how much water a pool holds before you dose it. Each one is built around the arithmetic rather than around a sign-up form.

What we put on every tool page

A result is only useful if you can see what produced it. Each tool page carries four things alongside the calculator: the formula or standard it applies, the assumptions baked into it, where the figure should not be relied on, and a link to the official source for any rate, limit or threshold involved. Where a number has a date attached — a tax year, a lottery draw, a rate table — the page says which date it is working from.

We would rather tell you a tool cannot answer your exact case than give you a confident number that is wrong. The limits sections exist for that reason and are written to be read, not to be skipped.

Guides, grouped by subject

Alongside the tools there is a library of written guides. They are grouped so that related pieces sit together and link to each other rather than floating alone:

• Money & Banking
• Insurance
• Taxes & Retirement
• Health & Wellness
• Tech How-To
• Travel
• Dream Meanings

Money, insurance and tax guides state the year and the figure they use, because those change annually. Health guides keep clinical claims to what published sources say and are explicit that they are general information rather than medical advice. Technical guides name the version they were written against — Apple silicon behaves differently from Intel, and Windows 11 moved half the settings.

Corrections

If a figure here is out of date or wrong, that is worth more to us than a compliment. Write to [email protected] with the page and what you saw, and we will check it against the source and fix the page rather than argue with you.