Tempo Stretch Ratio Calculator
Calculate duration change for a tempo conversion.
Your inputs
Calculation results
Formula & assumptions
New duration = old duration × original tempo/target tempo; pitch preservation depends on the editor.
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Tempo Stretch Ratio Calculator
Calculate duration change for a tempo conversion.
- Enter original tempo, target tempo, original duration using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Original tempo: 100 beats per minute Target tempo: 120 beats per minute Original duration: 180 seconds Speed multiplier: 1.2 Duration multiplier: 0.83333333 New duration · seconds: 150 Speed change · percent: 20
Questions & answers
What does Tempo Stretch Ratio Calculator calculate?
Calculate duration change for a tempo conversion.
Which units should I enter?
Original tempo uses beats per minute. Target tempo uses beats per minute. Original duration uses seconds. Convert values to these units before calculating.
Which formula does it use?
New duration = old duration × original tempo/target tempo; pitch preservation depends on the editor.
What does the included example show?
Original tempo: 100 beats per minute; Target tempo: 120 beats per minute; Original duration: 180 seconds. Result: Speed multiplier = 1.2; Duration multiplier = 0.83333333; New duration · seconds = 150; Speed change · percent = 20.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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