Audio/Video Sync Offset Calculator
Convert an A/V sync error between milliseconds and frames at any rate, and check it against the EBU R37 ±40 ms perceptibility limits.
We tolerate audio arriving a little late (sound travels slower than light, so the brain expects it) far less than early: EBU R37 sets the undetectable window at +45 ms (late) to −125 ms (early). 60 ms late is 1.5 frames at 25 fps — already past the comfortable limit and worth nudging.
Rule / Formula
Convert an A/V sync error between milliseconds and frames at any rate, and check it against the EBU R37 ±40 ms perceptibility limits.
About Audio/Video Sync Offset Calculator
Convert an A/V sync error between milliseconds and frames at any rate, and check it against the EBU R37 ±40 ms perceptibility limits. We tolerate audio arriving a little late (sound travels slower than light, so the brain expects it) far less than early: EBU R37 sets the undetectable window at +45 ms (late) to −125 ms (early). 60 ms late is 1.5 frames at 25 fps — already past the comfortable limit and worth nudging.
How to use Audio/Video Sync Offset Calculator
- 1Enter your values into the fields in Audio/Video Sync Offset Calculator.
- 2The result and any pass/fail verdict update instantly as you type — no button to press.
- 3Check the substituted formula and worked example to see exactly how the result was derived.
- 4Copy or note the result for your spec, delivery or planning.
Why use Audio/Video Sync Offset Calculator?
- ✓Runs entirely in your browser with instant, private results — no data leaves your device.
- ✓Built on a published reference: EBU R37 (relative timing of sound and vision).
- ✓Shows the governing formula and a worked example, so you can trust and check every result.
- ✓100% free with no sign-up, no watermark and no usage limits.
- ✓Works on any device — desktop, tablet or phone — and keeps working offline once loaded.
Frequently asked questions
What does Audio/Video Sync Offset Calculator do?+
Convert an A/V sync error between milliseconds and frames at any rate, and check it against the EBU R37 ±40 ms perceptibility limits. We tolerate audio arriving a little late (sound travels slower than light, so the brain expects it) far less than early: EBU R37 sets the undetectable window at +45 ms (late) to −125 ms (early).
Is my data private?+
Yes. Audio/Video Sync Offset Calculator runs entirely in your browser — your inputs are never uploaded, stored or logged.
What standard or source is Audio/Video Sync Offset Calculator based on?+
It follows EBU R37 (relative timing of sound and vision); ITU-R BT.1359. Always confirm against the current official document, as specifications and rates can change.
What formula does it use?+
Audio/Video Sync Offset Calculator uses: frames = (ms ÷ 1000) × fps; EBU R37 detectability: audio +45 ms to −125 ms relative to video. The tool shows this formula with your own numbers substituted so you can verify the result.
Is Audio/Video Sync Offset Calculator free to use?+
Yes — it is completely free with no account, no sign-up and no usage limits. There is no watermark and no paywall.
Embed Audio/Video Sync Offset Calculator on your website
Want Audio/Video Sync Offset Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/audio-video-sync-offset-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="Audio/Video Sync Offset Calculator — ToolJolt" loading="lazy"></iframe>Related Broadcast tools
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