UnitBuddy

Stop opening calculator tabs. UnitBuddy automatically turns every °F, mile, inch, pound, gallon, mph, or foreign price you meet online into the numbers you understand – right inside the page.

Why you’ll love it
One‑click clarity – “Bake at 425 °F” becomes “425 °F (220 °C)” and “£129.99” shows “£129.99 (€151, $162)”. No copy‑paste, no math.

Works everywhere you read – recipes, shopping sites, news, manuals, Reddit threads, travel blogs, comment sections – if there’s text, UnitBuddy can translate it.
Truly private & offline – all conversions happen in your browser; nothing is sent to any server, ever.

Lightning‑fast – a smart scanner updates the page in real time as you scroll or sites load new content.

Customisable – choose metric/imperial, pick your home currency, decide whether conversions appear inline, in tooltips, or only on hover.

Free forever – no sign‑up, no ads, no paywall.

Converts automatically
Temperature – °F ⇆ °C (+ Kelvin)

Length, area, volume & weight – inches, feet, yards, miles, acres, ounces, pounds ⇆ all metric units (and back)

Speed & fuel economy – mph, km/h, mpg, L/100 km
Currency – 150+ world currencies with daily European Central Bank rates
Time zones – turns “3 pm EST” or ISO date‑times into your local time (optional)
How it works

UnitBuddy lives entirely on your device. A lightweight content script spots numbers with unit labels, converts them using built‑in tables, then adds the translated value in subtle grey text (or tooltip). No extra permissions beyond the active tab. Toggle pause/whitelist sites from the toolbar pop‑up.