Video & subtitles
Timecode ↔ seconds & sum
Convert HH:MM:SS.mmm durations to seconds and add multiple durations.
Runs in your browser · No file or text uploads
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What Timecode ↔ seconds & sum helps you do
Turn editing notes into numeric durations or find the total runtime of several clips.
How to use it
- Enter seconds or a timecode on each line.
- Run conversion and addition.
- Review each duration and the total.
Input and output example
INPUT
00:01:30.500 45OUTPUT
90.5 + 45 = 135.5 seconds · 00:02:15.500
Supported formats and limits
- Nonnegative durations up to 1 billion seconds in total, with at most 1,000 input lines.
- Frame fields, negative durations and drop-frame notation are unsupported.
How the result is calculated
Minutes and seconds fields must be 00–59, with up to three fractional-second digits. HH:MM:SS and MM:SS are accepted. Output rounds to the nearest millisecond.
Frequently asked questions
Does 01:30 mean one hour and thirty minutes?
No. Two fields mean minutes:seconds, so it is 90 seconds. Enter 01:30:00 for one hour and thirty minutes.
Are start and end positions subtracted?
No. Each line is interpreted as a duration and added. Do not enter a timeline end position when you mean a clip length.