By Michael Hartley
There's a whole bunch of "single-operation" fractions calculators on this site, which show instant answers for specific operations. This page has a more general-purpose calculator. You have to click more buttons to get your answers, but all four basic arithmetic operations - plus, minus, times and divide - are included in one calculator.
Try it out!
On the other hand, if you want an offline calculator that you can see and touch and bring with you - I'd recommend this one for serious work, or this one for kids learning fractions