or tarckeemoon, depending
Joined: Dec 2005
Posts: 7,017
Likes: 2
From: the pesto of cities
Bikes: Davidson Impulse, Merckx Titanium AX, Bruce Gordon Rock & Road, Cross Check custom build, On-One Il Pomino, Shawver Cycles cross, Zion 737, Mercian Vincitore, Brompton S1L, Charge Juicer
Buy a floor pump with a gauge and use the portable only for emergencies on the road.
Flatting two tires at once is extremely rare so if you do have to fix a flat on the road you can compare by feel with the already-inflated tire. That should get you in the ballpark.
Keeping appropriate pressure in your tires will dramatically reduce tire-related problems out on the road. Buy a floor pump with a gauge and use it regularly.