SnapCalx – Calculator & Converter

Highlight any number on any page and calculate or convert it.

Stop switching tabs to run a quick calculation. SnapCalx lives in your browser and works on every page — highlight any number, expression, or amount and get your answer in a floating tooltip, instantly. Whether you're checking a price conversion, working out a percentage discount, or converting units while reading an article, SnapCalx is always one highlight away. Free features: - Instant maths — highlight any expression like 3*(12+4.5) and see the result - Percentage shortcuts — "15% of 340" or "20% off 50" - Interactive mode — select any number and tap +, −, ×, ÷ to keep calculating - Currency conversion — GBP, USD, EUR, JPY and more - Quick-calc popup — type any expression without leaving your current tab - Calculation history — your last 10 calculations, always at hand Pro features ($3.99/mo): - Full unit conversion — weight, length, area, volume and temperature Examples: "72 kg to lbs", "100 miles in km", "32°F to C", "500 sq ft to sq m" - Single-unit detection — select "72 kg" to see all conversion options at once - 150+ currency pairs with live exchange rates, updated daily - Single currency detection — select "£50" to see conversions to any currency - Full calculation history (last 50 items) How it works: 1. Highlight any number or expression on any webpage 2. A tooltip appears instantly with the result 3. Tap Copy to use the result anywhere — or keep calculating No account required for free features. Your calculations stay on your device and are never sent to our servers.