About ReckonBox

ReckonBox is a free set of calculators and tools, built and operated by DexTechLabs, an independent software company started by a team of eight developers. Every tool runs in your browser, needs no signup, and shows the formula behind the result, so the number is something you can check rather than take on faith.

Who builds this

We are software engineers, not a media company, so we build the tools the way we would want them built: the real formula on the page, every rate and rule taken from official data, and the math tested against known values before anything ships. We use AI as a drafting tool, under our direction, and verify every formula and figure ourselves before it publishes. DexTechLabs is our registered company, and you can find us on our website and LinkedIn.

Why we made it

Most calculator sites hide the math behind a single number and pad the page with filler. We wanted the opposite: a tool that shows its working, cites where its figures come from, and stays out of your way. Each page carries the formula, a worked example with real numbers, and the primary sources, so you can reproduce any result yourself in a spreadsheet or by hand.

How we keep the numbers right

Every figure on a tool comes from a source we read while building it, never from memory, and when sources disagree we use the authoritative one. Each formula is written as code and tested against results already known to be correct, and rate-sensitive tools carry a visible last-updated date. The methodology page lays out the full process.

What ReckonBox is not

Our tools explain what something is and how its math works. They do not tell you what to do with your money, your health, or your legal position. A result is an estimate based on your inputs and the current rules, not advice, so for a decision that matters, talk to a qualified professional.

Get in touch

Found a mistake, or want a tool we do not have yet? Tell us through the contact page, and we will take a look.