Chord charts are basically IKEA instructions for your hands — Roberto's full guitar chord chart already has almost every shape you'll ever need drawn out. The problem starts the moment you slide one of those shapes up the neck: the chart doesn't tell you what to call it anymore. Here's the two-fact cheat sheet that does, in about the time it takes to read this paragraph.
Fact 1 — one fret is exactly one semitone
Guitar frets are laid out as a straight chromatic scale, so moving any finger one fret up or down the neck moves the pitch by exactly one semitone. Slide a whole chord shape up two frets and you've moved every note in it — and the chord's name — up a whole tone.
Fact 2 — most movable shapes are named off a single string
The two shapes you'll use constantly both start life as open-position chords: barre the open E-major shape and its root sits on the low E string (6th string); barre the open A-major shape and its root sits on the A string (5th string). That's the backbone of the E-shape and A-shape barre chords inside the CAGED system. Learn the single note under your barre finger, and you've named the whole chord — no counting required.
The one thing worth memorizing
Just the natural notes on the low E string: E (open), F (1st fret), G (3rd), A (5th), B (7th), C (8th), D (10th), back to E (12th). There's no sharp or flat between E and F or between B and C, which is exactly why those two gaps are only one fret instead of two. The A string starts on a different letter, so the frets shift accordingly: A (open), B (2nd), C (3rd), D (5th), E (7th), F (8th), G (10th), back to A (12th). Learn both strings once and every E-shape or A-shape barre chord names itself on sight. For the full picture, the fretboard note map and the complete chord chart → are the deep-dive version; this is the fast one.
If this saved you thirty seconds of finger-counting, you can throw a coffee my way on Patreon — no pressure, purely for the riffs. Now go name some chords like you actually know what you're doing.