Semitone Calculator – Calculate Semitone Changes Online

Semitone Calculator — Music Theory Reference Tool

Calculate intervals, transpositions, frequencies, and scales. Everything musicians need to understand semitones and plan transpositions. Reference data, educational tool, and quick calculator in one.

What Is a Semitone?

A semitone is the smallest interval in Western music. It’s 1/12 of an octave. On a piano keyboard, each key (black or white) is one semitone from the next.

Examples:

• C to C# = 1 semitone (minor second)
• C to D = 2 semitones (major second)
• C to E = 4 semitones (major third)
• C to G = 7 semitones (perfect fifth)
• C to C (next octave) = 12 semitones

All Western music comes from these 12 semitones.

Five Calculators in One Tool

Calculator 1: Interval Finder

Tells you the musical interval between any two notes.

Select Note 1 and Note 2. Instantly see: interval name (Major Third), semitone distance (4 semitones), frequency ratio (1.26:1).

Use for:

• Guitarists learning fret intervals
• Singers understanding vocal ranges
• Composers finding harmonies
• Students learning music theory

Calculator 2: Transposition Calculator

Shows what note you get when shifting up or down by semitones.

Enter starting note + octave, then semitone shift (e.g., -3). See result note and frequency shift (e.g., D4 becomes A3).

Use for:

• Vocalists transposing songs to their range
• Producers planning key changes
• DJs finding compatible keys
• Teachers demonstrating transposition

Calculator 3: Frequency Lookup

Two-way conversion between notes and frequencies.

Note → Frequency: Enter any note (A4) → see 440 Hz (standard concert pitch)

• Sound engineers mixing
• Synthesizer programmers
• Teachers explaining pitch vs frequency
• Acousticians and researchers

Frequency → Note: Enter frequency (300 Hz) → find nearest note (D#4)

• Identifying mystery frequencies
• Tuning instruments
• Audio analysis

Calculator 4: Scale Generator

Shows all notes in any scale, with frequencies.

Choose root note (C) + scale type (Major, Minor, Dorian, Blues, Pentatonic, etc.) + octave range (1-3).

Available scales:

• Major (bright, happy)
• Natural Minor (sad, introspective)
• Harmonic Minor (classical, mysterious)
• Modal scales (Dorian, Phrygian, Lydian, Mixolydian)
• Pentatonic (simple, folk-like)
• Blues (soulful)

Use for:

• Guitarists knowing which frets fit scale
• Pianists knowing which keys fit
• Producers building melodies
• Songwriters ensuring notes work together
• Students learning scale patterns

Calculator 5: Reference Table

Complete frequency reference for all notes (C0-B8).

Browse every note with exact frequencies and MIDI numbers. Perfect for mixing reference, MIDI programming, tuning instruments, learning music theory.

Common Use Cases

Use Case 1: Vocalist Transposing

Original key awkward? Transposition Calculator shifts down 5 semitones into perfect range.

Use Case 2: Guitarist Learning Chords

Major chord = Major Third (4 semitones) + Minor Third (3 semitones). Understand construction on any fret.

Use Case 3: Music Teacher

“What’s a tritone?” Interval Finder shows C to F# = Tritone (6 semitones) = “Devil’s interval.” Students see semitone count, ratio, name all together.

Use Case 4: Producer Creating Pads

Melody at 261 Hz? Frequency Lookup shows = C4. Build pad around C4, E4, G4 for harmony.

Use Case 5: Composer Modulating

From G Major to B Major? Transposition Calculator shows G → B = up 4 semitones (major third).

Music Theory Basics

The 12 Notes: C, C#/Db, D, D#/Eb, E, F, F#/Gb, G, G#/Ab, A, A#/Bb, B (then repeats in next octave)

Octaves: Notes repeat every 12 semitones. Frequency doubles (C4 = 261.63 Hz, C5 = 523.25 Hz).

Interval Reference:

• Minor Second = 1 semitone
• Major Second = 2 semitones
• Minor Third = 3 semitones
• Major Third = 4 semitones
• Perfect Fourth = 5 semitones
• Tritone = 6 semitones
• Perfect Fifth = 7 semitones
• Minor Sixth = 8 semitones
• Major Sixth = 9 semitones
• Minor Seventh = 10 semitones
• Major Seventh = 11 semitones
• Octave = 12 semitones

A4 = 440 Hz: International standard concert pitch. All notes defined relative to this.

FAQ

Q: What’s the difference between semitones and guitar frets?
A: Each fret = 1 semitone. Move up 5 frets = up 5 semitones.

Q: Can I use this to tune instruments?
A: Yes. Use Frequency Lookup to find exact frequency, then tune to that.

Q: What’s the difference between C# and Db?
A: Same pitch (enharmonic). C# is sharp, Db is flat.

Q: How do I transpose a song?
A: Use Transposition Calculator to find target note. Shift all song notes by that amount.

Q: What’s middle C?
A: C4 (middle of piano). Frequency: 261.63 Hz.

Q: Can I save calculations?
A: Use browser bookmark or screenshot to save results.

Q: Why A4 = 440 Hz?
A: International standard (1939). Some orchestras use 442 or 445 Hz (sharper).

Q: Is this for absolute beginners?
A: Yes! Educational content explains every concept. No prior knowledge needed.

Q: Can producers use this?
A: Yes! Frequency lookup, transposition, scale reference—all standard production tools.

Q: What’s equal temperament tuning?
A: The system used here. All 12 semitones equally spaced. Modern standard.