This free lip sync delay calculator converts an audio/video timing difference into milliseconds, seconds, video frames and audio samples. Use it when you know the measured offset and need a clear correction value for aligning sound with picture.
Enter the measured delay in milliseconds, frames or audio samples, or compare separate video and audio timestamps.
Lip sync depends on the timing relationship between a visible event and its matching sound. A person's mouth movement and the corresponding speech are an obvious example, but the same calculation can be used for any picture event paired with audio.
The calculator uses a simple sign convention: a positive offset means the audio occurs after the video, while a negative offset means the audio occurs before the video. Zero means that the two entered timing references have no measured offset.
If you are working with audio more broadly, the Audio Tools for Recording, Mixing, and Ear Training collection includes additional browser utilities. You can also experiment with signal balance in the Interactive Online Audio Mixer.
Find how far the matching audio event is from the visible event.
Enter milliseconds, frames, samples or two separate timestamps.
Select the video FPS and audio sample rate used by the material.
Use the displayed direction and equivalent offset value.
Knowing the size of a sync error is only half of the calculation. You also need to know its direction. A 120 ms difference could mean that the sound arrives 120 ms too late or that it arrives 120 ms too early.
A positive result means the audio event occurs after the corresponding picture event. To align the two in an editable timeline, the audio would normally need to move earlier by the displayed amount.
A negative result means the audio event occurs before the corresponding picture event. In that case, the equivalent correction moves the audio later.
Spoken material is especially easy to inspect against visible mouth movement. Related production resources include vocal and speech recording, commercial audio recording and audio content recording.
Example: +80 ms means the matching sound occurs 80 milliseconds after the picture reference.
A calculated value of 0 ms means the two timing references entered into the tool coincide.
Example: −80 ms means the matching sound occurs 80 milliseconds before the picture reference.
A lip sync delay calculator online is useful when one system reports a delay in milliseconds while another expects a frame-based value. The same amount of elapsed time represents a different number of frames depending on the video's frame rate.
For example, 100 milliseconds equals 2.4 frames at 24 fps and 6 frames at 60 fps. The time difference has not changed; only the frame-based description of that duration has changed.
Fractional rates are handled internally as their standard rational values: 23.976 uses 24000/1001, 29.97 uses 30000/1001 and 59.94 uses 60000/1001. This provides a more precise conversion than performing the arithmetic with only the shortened decimal label.
| Delay | Frame Rate | Frame Duration | Frame Offset |
|---|---|---|---|
| 100 ms | 24 fps | 41.667 ms | 2.400 frames |
| 100 ms | 25 fps | 40.000 ms | 2.500 frames |
| 100 ms | 29.97 fps | 33.367 ms | 2.997 frames |
| 100 ms | 30 fps | 33.333 ms | 3.000 frames |
| 100 ms | 50 fps | 20.000 ms | 5.000 frames |
| 100 ms | 60 fps | 16.667 ms | 6.000 frames |
Milliseconds and frames are convenient for describing visible timing differences, but an audio editor can work at the finer resolution of individual samples. The calculator therefore also expresses the same offset as an audio sample count.
At a sample rate of 48,000 Hz, one second contains 48,000 samples. A 100 ms offset therefore corresponds to 4,800 samples. Changing the sample rate changes the sample count representing that same duration.
For hands-on audio practice, try the Mixer Console Simulator. Musicians preparing material can also explore song demo production and music recording.
The calculator does not need the original media file because its job begins after a timing difference has been identified. Enter the measured offset directly, or enter the time of the visible event and the time of its matching sound.
In Two Timestamps mode, the calculator subtracts the video event time from the audio event time. If the audio timestamp is later, the result is positive. If it is earlier, the result is negative.
The output then provides equivalent values in several units. This is useful when a measured difference is expressed in one format but the control or timeline you are adjusting uses another.
If your work begins with recording rather than an existing timeline, the First Time Recording Studio Guide explains session preparation. You can also read about recording confidence or explore recording approaches for different music genres.
Explore recording, mixing and mastering services, learn more about mixing and mastering workflows, or read how long vocal recording can take. Artists planning a dedicated session from outside the area can also review the New York recording travel guide.
Enter the measured audio/video difference and instantly compare the same offset in milliseconds, seconds, frames and audio samples.
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