What is a playback speed ratio?

It is the factor by which you speed up or slow down a player. A ratio of 1.25 means 25% faster; 0.8 means 20% slower. Multiply the original BPM by this ratio to confirm you land on the target BPM.

Will pitch change when I alter playback speed?

In a basic speed change (without pitch correction) yes — faster playback raises pitch. Most DAWs and DJ software offer independent time-stretch and pitch-shift so you can change tempo without affecting key.

What is the maximum safe time-stretch without artefacts?

As a rule of thumb, stretching within ±25% (ratios 0.75–1.25) sounds natural with modern algorithms. Beyond that, artefacts become audible on complex material, though transient-heavy content tolerates wider ranges.

How do I find the BPM of a song?

Tap a beat counter (including tools on this site), use a DAW's beat-detection feature, or check a database such as Tunebat or Songbpm.com. Most modern DJ software auto-detects BPM on import.

Does this tool process my audio file?

No. All calculations are pure math performed in your browser. No audio is uploaded or modified — you apply the resulting ratio in your DAW or media player.

Why is my new duration longer when I lower the BPM?

Slowing down a track stretches it in time. If the speed ratio is less than 1 (target BPM original duration.

Tempo Changer

Name: Tempo Changer
Availability: InStock
Author: Nham Vu

Enter your original BPM and target BPM to get the exact playback speed ratio, new track duration, and a full tempo reference table.

Tempo Settings

Original BPM

Target BPM

Track Duration (optional)

Leave blank to skip duration calculation.

Enter BPM values and click Calculate to see results.

Speed Ratio

—

× playback speed

Pitch Shift

—

semitones

Tempo Reference Table

Based on original BPM

Speed	BPM	Duration	Semitones

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Summary

Enter your original BPM and target BPM to get the exact playback speed ratio, new track duration, and a full tempo reference table.

How it works

Enter the original BPM of your track in the first field.
Enter the target BPM you want to reach.
Optionally input the track duration (minutes and seconds) for an adjusted length calculation.
The speed ratio is computed as Target BPM ÷ Original BPM.
New duration is Original Duration ÷ Speed Ratio.
The reference table shows BPM and duration at seven common speed multipliers.

Use cases

DJs matching a track to the set BPM before mixing.
Producers time-stretching stems to a project tempo.
Dance instructors finding a safe stretch percentage for class choreography.
Runners calculating what BPM a playlist will hit at a given speed bump.
Music students analyzing how tempo shift affects feel and groove.
Podcasters adjusting speech-rate audio files to target durations.
Fitness coaches syncing workout music to target heart-rate cadence.
Game developers tuning adaptive music loops to match scene pacing.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu