# How to Find a Song’s Key and BPM

> How to find the key and BPM of a song or beat — why it matters for writing and singing in tune, and how to detect key and BPM automatically on your phone.

[All guides](/blog)

# How to Find a Song’s Key and BPM

Updated June 2026 · by Loopin

Knowing a beat’s key and tempo makes everything easier — writing melodies that fit, singing in tune, and matching ideas together. Here’s how to find both.

## Why key and BPM matter

**BPM** (beats per minute) is the tempo — it sets the pace of your flow and how your syllables land. The **key** is the home note set your melody and harmonies revolve around; singing or toplining in the wrong key is what makes a take feel “off.”

## Finding the BPM

You can tap along to the beat for four bars and average it, or use a tempo detector. The fastest way: let it detect automatically. [Loopin](/#download) reads the BPM the moment you import a beat.

## Finding the key

By ear, hum the note the song “resolves” to and find it on a keyboard. Or use automatic detection — Loopin estimates the key for your imported beat so you can write in tune without guessing.

## Use it while you write

With key and BPM known up front, your melodies fit, your harmonies stack, and your features match. It’s a small thing that makes finished songs sound a lot more professional — and it pairs well with a clean [master](/mastering) at the end.

## Related reads

- [What is Loopin?](/blog/what-is-loopin)
- [How to write a song](/blog/how-to-write-a-song-for-beginners)
- [Find & organize beats](/blog/find-and-organize-beats-for-songwriting)

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Source: https://onloopin.com/blog/how-to-find-song-key-and-bpm