Capo position

Which fret turns shapes you know into the key you want, and how it plays.

It runs entirely in this browser tab: nothing you type is uploaded, and every published figure on the result says where it came from.

Settings

Instrument: Four tunings, because those are the four that differ. Choices: Guitar, Ukulele, Baritone ukulele, Bass.
Direction of travel: An hour later is easy; an hour earlier is not, which is why east is harder. Choices: Where does the capo go, What sounds at a fret.
Fret: Only read in the other direction, where the fret is known. A number from 0 to 12.
Accidentals: The real signs are not in this interface's typefaces; the plain spelling always draws. Choices: Written as # and b, The real music signs.

Where do the published figures come from?: From the tables the trade uses: saponification values from the oil chemistry, yarn yardages from the craft council's weight standards, filament densities from the material data sheets. Every one is a figure for a *kind* of thing, and the result names what beats it — the bottle, the ball band, the spool.
Is the lye calculator safe to make soap from?: It is arithmetic on published values, and the result carries the safety notes and says to check any recipe against a second calculator before making it. Lye is caustic; the superfat is the margin for a weighing error and is not there to be set to nought.
Why does the chocolate tool not just say whether the dog is fine?: Because that is a vet's decision and not a table's. What it gives is the theobromine dose, the whole published ladder with the dog's own row marked, and how much of that chocolate would reach the first threshold — and it says to ring a vet on every result, including the low ones.
Is anything I type kept?: No. There is no account and no server: the page runs in this tab, works the answer out and forgets it when you close it. That holds for the baby log and the allowance tracker as much as for the yarn estimate.

Circle of fifths
Every key with its signature, its relative and the seven chords built on its scale.

Chord progressions
Fourteen patterns that recur in published music, written out in your key.

Transpose a chart
Moves the chords and leaves the words exactly where they were.

Chord diagrams
Draws the shapes you type as boxes, with the notes they sound underneath.