Stick this in your ear, genius. The Plant Bike dial tire gauge is one of those insanely useful little devices that at $15 is a no-brainer: just pick one up. You'll end up using it for all things inflatable: cue the imaginary playmate.
The gauge has a chrome tippy thing that fits over Presta valves, like on your bike. Just unscrew it and it works with Schraders, like on your car. I keep in my car's glove box since if I'm biking, I'm usually starting from my garage where my car is anyway and if I'm not I probably drove to the trailhead. It's handy these days since many gas stations don't have a pressure gauge on their air hoses.
Easily readable it measures up to 140psi or 10 wimpy European kg/cm2. The angled valve is just right to get a good reading, and even better the reading sticks until you press a little button. Pretty tough too. I like it a lot more than the fussy gauge built into my various pumps. Note to yourself: there's a little rubber thingy in the chrome housing that fits over the valve stem. It will fall out if you don't pay attention when removing it, so word to the wise.