Easily convert pixels to rem.
# get the rem value, given a pixel value
> pxrem 19
1.1875
# specify the number of decimal places to return (default: 8)
> pxrem 19 -p 2
1.19
# specify the base pixel size to use (default: 16px)
> pxrem 19 -b 10
1.9
# get the pixel value for a given rem value
> pxrem 2.25 -r
36