Quick answers, one click away
Click the Calculator Hub icon in your browser toolbar and get an instant answer without opening a new tab: a live math expression evaluator, everyday date tools (including today's Hijri date), and currency conversion with live exchange rates. When a task is too big for a popup — a mortgage, a solar array, a room of tiles — the big Open Full Calculator Hub button takes you straight to the complete site.
What's inside
Math
A live expression calculator: + − × ÷, powers, parentheses and spreadsheet-style percentages (200+10% → 220). Your last few calculations are remembered on your device.
Dates
Today's Gregorian and Hijri (Umm al-Qura) date at a glance, exact age from a date of birth in years, months and days, days between two dates, and a countdown to any date.
Currency
Convert between 30 currencies with live rates served by smartcalc-tools.com, cached on your device so the popup still works offline with your last-known rates.
The popup — the same dark-navy and brass look as the Calculator Hub site.
How to install
Chrome, Edge, Brave or Opera
- Download the zip above and unzip it to a folder you will keep (for example
Documents/calculator-hub-extension). - Open
chrome://extensionsin your address bar (Edge:edge://extensions). - Turn on Developer mode — the toggle in the top-right corner.
- Click Load unpacked and select the unzipped folder.
- Pin the extension from the puzzle-piece icon so the button is always one click away.
Firefox
- Download and unzip the extension folder.
- Open
about:debugging#/runtime/this-firefox. - Click Load Temporary Add-on and choose the
manifest.jsonfile inside the folder.
The extension is pending publication on the Chrome Web Store and Mozilla Add-ons; once listed, installing will be a single click from the store page. Loading it unpacked as above works fully right now.
Privacy
The extension follows the same zero-data promise as the website. Every calculation — math, dates, age, countdowns — runs entirely on your device. Nothing you type is ever transmitted. The single network request the extension makes is a daily fetch of exchange-rate numbers from smartcalc-tools.com/api/rates, and the response is cached only in your browser's local storage. There are no ads, no analytics and no tracking inside the extension.
Why an extension?
- Speed. Type
1280*1.15or check today's Hijri date without opening a tab or losing your place. - Always with you. The toolbar button works on every page — shopping, banking, forums, homework.
- A doorway, not a walled garden. The popup handles the quick questions; everything complex is one click away at the full Calculator Hub with 20+ calculators, in-depth guides and games.
Frequently asked questions
Is the extension really free?
Yes — completely free, with no ads inside the popup, no accounts and no premium tier.
What data does it collect?
None. All calculations run locally. The only network traffic is the daily exchange-rate fetch, and it carries nothing about you.
Does it work offline?
Math and date tools work fully offline. Currency conversion uses your last cached rates, or built-in reference rates if none have been fetched yet.
Which browsers does it support?
Any Chromium browser version 88 or later (Chrome, Edge, Brave, Opera) and Firefox 115 or later, from the same package.
How do the percentage calculations work?
Like a spreadsheet: a percent after a number means that share of the value before the operator. 200+10% is 220, 200-10% is 180, and 85*15% works out a 15% tip of 85.