rob's timecode calculator

Why this calculator exists

If you edit video, mix sound, build motion graphics, or prep cue sheets, you already know the pain: time math gets tedious fast. A short note like “start this at 01:02:13:18 and trim 12 seconds, 8 frames” can turn into manual counting, re-checking, and mistakes.

rob's timecode calculator is built for speed and confidence. It gives you practical operations in one place: add durations, subtract durations, find differences, and convert between timecode and total frames. No spreadsheet gymnastics required.

How to read a timecode value

This tool uses the common HH:MM:SS:FF format:

• HH = hours
• MM = minutes
• SS = seconds
• FF = frames

Frames are counted according to your chosen frame rate. At 25 fps, valid frame values are 00 through 24. At 30 fps (or 29.97 non-drop display), valid frame values are 00 through 29.

Common workflows this solves

1) Add handles and slates

Need to add a 2-second slate and 12-frame handle to every clip start? Use Add Duration mode and move quickly through your list.

2) Pull exact segment lengths

If editorial gives you in/out points, switch to Difference Between A and B. You get total duration immediately, plus frame and second equivalents for logging.

3) Build frame-accurate notes

Producers and clients often ask for “how many frames?” at specific rates. Use Timecode to Frames to produce an exact count for QC notes, VFX pulls, or animation timing.

Frame rates and practical notes

This page computes using non-drop-frame math. For decimal NTSC rates like 29.97 and 59.94, the display frame field still behaves as 30/60-based counting while seconds are shown using the selected decimal frame rate. That keeps day-to-day calculations predictable for many editorial tasks.

If your pipeline depends on strict broadcast drop-frame timecode rules (especially long-form clock time alignment), verify results against your NLE settings and house standards.

Tips to avoid costly timing errors

• Confirm frame rate before doing any math.
• Keep one project, one fps policy—mixing rates creates confusion quickly.
• Use copy/paste for timecodes to avoid transcription mistakes.
• When in doubt, compare your result against your timeline display.
• Document whether your delivery is drop-frame or non-drop-frame.

Quick example

Suppose clip A starts at 01:10:15:12 and you need to add 00:00:20:08 at 25 fps. The calculator returns 01:10:35:20. You also get total frame and second values for reporting.

Final thought

Timecode math should support creativity, not slow it down. Use this tool as your scratchpad for fast, frame-aware decisions across editing, sound, color, motion, and delivery prep.