Chord note calculator
C major gives C, E and G, labeled P1, M3 and P5. Enter a root and a quality such as maj7, sus4 or m7b5 to see every tone with its interval name and half-step distance, ready for a fretboard or piano chart. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Root pitch class
- C
- Quality
- maj
- Root pitch class
- 0
- Quality input
- maj
- Symbol
- C
- Note count
- 3
A chord is a stack of pitch classes measured from a single root by fixed interval formulas. Guitarists, pianists, songwriters, and theory students constantly ask which notes sit inside C major, F sharp minor seventh, or B flat dominant ninth—and which interval each tone is from the root. This chord note calculator answers that question deterministically: send a root pitch class and a quality token, and receive ordered note names, classical interval labels such as M3 and P5, semitone offsets, and a compact chord symbol. Unrecognized qualities fail with a clear invalid input error so pipelines never invent tones for a typo.
Choosing the root and a supported chord quality
Provide two required fields. The root is a pitch class letter from A through G with an optional sharp or flat accidental—examples include C, F sharp written F#, B flat written Bb, and the unicode forms with sharp and flat signs. Case is ignored for the letter, and a trailing octave digit such as C4 is stripped so classroom spellings still parse.
The quality field selects the interval formula: maj or major for a major triad, min or m for a minor triad, dim and aug for diminished and augmented triads, sus2 and sus4 for suspensions, 7 or dom7 for dominant seventh, maj7 and min7 for major and minor sevenths, dim7 and m7b5 for fully and half diminished sevenths, 6 and m6 for sixth chords, 9 maj9 min9 and add9 for common ninth shapes, and 5 for a power chord of root and fifth.
Prefer spelling the root with the accidental you want reflected in the answer: flat roots prefer flat note names in the tone list when enharmonic choices exist, which keeps B flat major reading as Bb D F rather than A sharp respelled tones.
What you can do with it
Practice sheets and theory homework
Students enter a root and quality, check the listed notes and intervals against their own spelling, and see a clear error when they type an unknown quality by mistake.
Songwriting and lead-sheet tools
Apps expand chord symbols into tone lists for fretboard diagrams, piano overlays, and MIDI preview without embedding a full music-theory engine.
FAQ
How do I get the notes of a chord?
The response includes notes, intervals, semitones, and a structured tones array.
What happens if the chord quality is unrecognized?
Only the published quality set is accepted so the calculator never invents chord tones for a typo.
Is the chord note calculator free?
The browser tool runs free on your device.
Does this transpose chords or return frequencies?
No. This calculator only expands a root plus quality into notes and intervals. Use a transposition calculator to shift symbols by semitones, or a note frequency calculator for equal-temperament Hz.
Why does B flat major show Bb, D and F instead of sharps?
A root written with a flat makes the tone list prefer flat names whenever two spellings sound the same. Write the root with the accidental you want to read, and the chord follows that family.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/hobby/chord-notes \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"root":"C","quality":"maj"}'const res = await fetch("https://api.kit.forhosting.com/hobby/chord-notes", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"root": "C",
"quality": "maj"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/hobby/chord-notes",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"root": "C",
"quality": "maj"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/hobby/chord-notes", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"root":"C","quality":"maj"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"root":"C","quality":"maj"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/hobby/chord-notes", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"root": "C",
"quality": "maj"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "hobby.chord_notes",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Choosing the root and a supported chord quality
Aliases such as major7, minor, diminished, and halfdim map to the same formulas so human input stays flexible. If the quality token is not in the supported set, the engine raises invalid_input naming the bad quality—this product never guesses a nearest chord.
Reading notes, intervals, semitones, and the chord symbol
The notes array lists each chord tone in stacking order from the root upward using the chosen accidental preference. Parallel arrays intervals and semitones give classical labels such as P1, m3, M3, P5, m7, M7, and M9 alongside the exact half-step offsets used by the formula, including compound ninths at fourteen semitones for ninth chords. On success the response echoes the normalized root, its pitch class integer from zero at C through eleven at B, the canonical quality label, and the quality string you sent. The tones array combines those fields per degree with pitch_class for UI tables and grading oracles. The formula string joins offsets with hyphens for a compact theory fingerprint, symbol builds a short display name such as Am or Gmaj7, and method is always interval_formula_mod12 so clients can branch without sniffing shapes. Missing root, missing quality, illegal pitch spellings, and unknown qualities all fail with invalid_input and are not charged.
API usage, pricing, practice workflows, and practical limits
Call the free in-browser chord note calculator for practice sheets, fretboard quizzes, lead-sheet checks, and classroom demos without installing a DAW plugin or music-theory library. Source inputs follow the same retention rules as other KIT parse items. Authors shipping SDKs can map the tones array directly into tables that show degree, note, interval, and semitone columns—the same shape students write when they spell chords by hand from a root and quality. Send a JSON body with required string fields root and quality, or use documented aliases such as note and type when your client already speaks those names. Use the prepaid API when a tutoring platform, setlist tool, ear-training app, or content generator needs a stable contract under KIT balance at $0.002 per successful item; validation failures never consume balance after the engine rejects the request. Pair this endpoint with a music transposition calculator when you already know the chord symbol and need it moved by semitones, or with a note frequency calculator when the next step is equal-temperament Hertz for synthesis. This capability returns pitch classes and intervals only—it does not voice chords across octaves, suggest inversions beyond the stacked formula, analyze audio, or invent jazz alterations outside the published quality table.
Integration use cases
Tutoring platforms and drills
Curriculum generators produce deterministic chord-tone answers for auto-graded quizzes and flashcards at a stable prepaid unit price.
Technical questions
Which chord qualities are supported?
Common forms include maj, min, dim, aug, sus2, sus4, 7, maj7, min7, dim7, m7b5, 6, m6, 9, maj9, min9, add9, and power chord 5, plus frequent aliases such as major, minor, and dom7.