I've been using
Calculator TRUE for all kinds of calculations and conversions. What I really like about it is the variety - they have calculators for pretty much everything you can think of: unit conversions (length, weight, temperature, etc.), date and time calculations (countdowns, days between dates), construction calculators (pool volume, materials), finance calculators, and more. The interface is clean and straightforward - no annoying ads covering half the screen or popup windows trying to get you to download something. Everything just works without fuss. I have it bookmarked and probably use it 2-3 times a week for random things - converting measurements for recipes, figuring out how many days until a deadline, calculating project costs, whatever comes up. The calculators are accurate and update in real-time as you type, which is really handy. They also have all the common converters you actually need rather than obscure ones nobody uses. My favorite features: the step calculator for fitness tracking, the margin calculator for my small business, and all the length/weight converters for international shopping. It's become my go-to site whenever I need to figure something out quickly. Way better than trying to do mental math or fumbling with formulas!
