This online cello tuner recognizes the string you played and shows the note, the cents and which way to adjust. The cello is tuned C G D A (C2 G2 D3 A3), the viola's notes an octave lower, with the strings a perfect fifth apart. The C string is only 65 Hz, so where you put the phone matters.
Choose A = 440 or 442 Hz and tap any string to hear its reference tone. It runs in your browser with no app and no sign-up, and the sound never leaves your device.
How to use it
- Tap Turn on microphone and allow access. Rest the phone on a music stand about a foot (30 cm) from the cello, level with the f-holes.
- Play the open string with a long, weighted bow stroke and let it ring.
- Needle to the left: the string is flat, so tighten. To the right: it's sharp, so loosen. In the green (±5 cents) it's in tune.
- Fine-tune with the fine tuners on the tailpiece (clockwise raises the pitch); for bigger corrections use the pegs, turning slowly and pushing in.
- Tune the A first, then D, G and C, and check the A again at the end.
Tuning in fifths and the cello's C
Many cellists set the A with a tuner and the other strings by ear, playing two together until the beating stops. A pure fifth is about 2 cents wider than the tuner's, so working down from the A, the C ends up about 6 cents below zero.
In a quartet or orchestra that sounds fine. With piano, keep the G and C closer to zero, or the open C will sound flat against it.
Pegs or fine tuners
Most cellos have a fine tuner at least on the A string. Use it for the final adjustment; when it reaches the end of its travel, back it out to the middle and correct with the peg. If the bridge starts leaning after a lot of tuning, straighten it before you go on.
Tips
- If the C string won't register, move the phone closer to an f-hole and bow a little harder, near the bridge.
- Fans and air conditioners make noise right in the cello's low range; switch them off while you tune.
- Tune in playing position, with the endpin firmly on the floor: the instrument vibrates freely and the reading is steadier.
- A fine tuner screwed all the way in can touch and scratch the top; check under the tailpiece.
Frequently asked questions
What are the cello string notes?
From lowest to highest: C, G, D and A (C2 G2 D3 A3), at about 65, 98, 147 and 220 Hz with A = 440.
How do I tune a cello as a beginner?
Turn on the microphone, play the A string and adjust it with the fine tuner until it's green, then do D, G and C. Use the pegs only when a string is far off, ideally with your teacher's help at first.
Should I tune with the pegs or the fine tuners?
Fine tuners for a few cents, turning clockwise to raise the pitch; pegs for anything bigger, or when the fine tuner has run out of thread.
Why is my cello's C string hard for a phone to read?
Small microphones capture little below 100 Hz, and the cello's C is about 65 Hz, so the detector sometimes hears an overtone more than the note itself. Move the phone closer, use a firm bow and cut low background noise.
Should I tune my cello to 440 or 442 Hz?
For practice, 440 Hz; with an orchestra, the group's reference, often 442 Hz. The cello's A string is A3 (220 or 221 Hz), but there's no math to do: the selector recalculates every string.
How often should I tune my cello?
Every time you play, and again after changes in temperature or humidity. A quick check of the A before practice usually shows whether the other strings need work.
Is a violoncello the same as a cello?
Yes. Violoncello is the full Italian name; cello is the everyday short form.