UnitMojo started as a unit converter, built for a web that no longer needs to look like the old ones. It has since grown into something a little broader: calculators for the real situations behind the numbers - a mortgage with an offset account, a raise measured against inflation, a rental property with a mortgage attached. The starting question is still the same one: what would this look like if we started over?
The older sites in this space share the same shape. A category page, two dropdowns, a Convert button, one answer, and start over if you want a different unit. Somewhere in there, an ad loads above the result and another below it. None of that is a mistake exactly, it's just how converters were built fifteen years ago, and nobody has gone back to rebuild the basic idea since.
UnitMojo reads a plain sentence instead of two dropdowns. Type 180 lb to kg or how many oz in a cup, and it answers, then shows every other unit in that category at once, so a different target is one tap away instead of a full restart.
The same instinct - rebuild the basic idea instead of copying it - carried over once it became clear a lot of real questions are not really unit questions at all. "Is my offset account actually working" and "did that raise beat inflation" are not conversions, but they deserve the same standard: a real answer, worked from the actual mechanics, not a rounded guess.
Not one audience - several, each with a specific moment in mind. A student checking their GPA before applying somewhere, or double-checking a sig-figs answer before a chemistry exam. A home cook mid-recipe with a phone propped against a mixing bowl, converting a cup of flour that a recipe from another country wrote in grams. A runner working out the pace they need for a race goal. Someone at a car parts counter converting a torque spec, or checking a tire pressure sticker in psi against a pump that only shows bar. A traveller weighing a suitcase before a flight. And now, further out from pure conversion: someone with an offset mortgage who wants to check their own bank statement rather than take the number on trust. Someone deciding whether a rental property is actually worth what it costs, worked out from the real cash flows, not a gut feeling. Someone comparing a raise to inflation to find out whether it was actually a raise. These are not abstract use cases - each tool on this site was built around one of these specific moments, not a generic "convert anything" or "calculate anything" mandate.
Exact factors, not rounded guesses. An inch is 25.4mm because that's the legal international definition, not an approximation. Every conversion factor on this site is checked against authoritative sources and covered by an automated test that would fail if anyone, including us, ever got it wrong. That's not a marketing line, the test suite is real and it runs on every change.
Regional differences get flagged, not hidden. A US cup, a UK cup, and an Australian cup are three different volumes. Most converters silently pick one and never mention it. UnitMojo shows all three side by side the moment it detects the word is ambiguous.
Numbers anchored to something real. A bare figure like "42,195" means nothing on its own. UnitMojo ties it back to something you can actually picture, a marathon, a Big Mac, the height of a mountain, so a result carries some sense of scale, not just digits.
Real mechanics, not a single formula. A loan with an offset account is not one equation - it is a month-by-month simulation of a balance that changes every day. A retirement projection that treats a career break as an actual input, not something folded into an average rate, needs to model each stage separately. Where the honest answer requires more than a formula, that is what gets built.
Sources named, not just claimed. Contribution-rate guidance for Australia, the UK, the US, and Canada links back to the ATO, MoneyHelper, Fidelity, and Sun Life directly, not to a summary of a summary. Where a figure is our own calculation rather than someone else's published number, the method is explained on the page, not hidden behind the result.
Not financial advice, said plainly. These tools show what the numbers do under the assumptions entered - they do not know your full situation, and they say so. A calculator that quietly implies more certainty than it has is worse than one that admits its limits.
It's easy to claim a tool is "better" than what's already out there. Here's a specific, checkable example instead: the significant figures calculator rounds 9.995 to 3 sig figs correctly, giving 10.0. Try that same input on most calculators built with ordinary floating-point math and you'll get 9.99 - not because the formula is wrong, but because 9.995 genuinely can't be stored exactly in binary, and gets silently rounded down before the calculator even starts working with it. We found this by testing against the edge case, not by assuming standard math would hold up, and rebuilt the rounding to work on the actual digits typed rather than a lossy internal copy of them.
The same standard applies elsewhere: wind chill and heat index use the exact NWS and NOAA formulas, with their real validity ranges stated rather than extrapolated past where they mean anything. The luggage checker starts from the common industry baseline and adds individual airlines only where the carrier's own published policy could be verified, each shown with the date it was checked - a deliberately short list rather than a long one padded with numbers we could not confirm. The turkey roasting time cites USDA's own guidance rather than a rounded rule of thumb. Where we cite a figure, we try to name where it came from.
In the interest of not overselling this: most of these tools are new, and most of what guided which ones got built is informed research into what people search for and what similar tools elsewhere already offer, not confirmed usage on this site yet. We don't have years of visitor data the way older, larger sites in this space do, and that's worth saying plainly rather than implying otherwise. What we can stand behind is the accuracy of what's here, and that the tools were built around real, specific situations rather than a generic checklist.
The converter itself doesn't run ads, doesn't set tracking cookies, and doesn't call out to a server after the page loads. That's a real architectural choice, not a slogan: the whole unit table ships with the page, so it keeps working with no connection at all.
We also don't guess. If two units genuinely don't measure the same kind of thing, like kilograms and litres with no ingredient specified, UnitMojo says so plainly instead of inventing a number that looks confident and isn't.