Free Tool for Video Editors

TC-100 Timecode Calculator

A calculator built specifically for editors who work in drop-frame and non-drop-frame timecode — add, subtract, multiply, and divide timecodes without doing the SMPTE math in your head.

Why this exists

Drop-frame timecode is deceptively easy to get wrong. Certain frame numbers — :00 and :01 at the start of most minutes — simply don’t exist, skipped on purpose so the timecode stays roughly in sync with real clock time. Add two timecodes together by hand, or in a calculator that doesn’t understand the rule, and you can end up a few frames off without realizing it. TC-100 handles that correction automatically, every time.

What it does

• Full drop-frame and non-drop-frame support at 60, 59.94, 30, 29.97, 24, and 23.976 fps, plus any custom frame rate you need.
• Add, subtract, multiply, and divide timecodes the way you’d expect from a real calculator — type digits, press an operator, keep going.
• Chain calculations like an adding-machine tape: keep adding clip durations one after another, or hit = again to repeat the last operation.
• A built-in history log so you can review your work or jump back to an earlier result with one click.
• Memory keys (M+, M−, MR, MC) for holding a running total while you work through other numbers.
• Runs standalone on both Mac and Windows — no install of any other software required.

Download

TC-100 is free. Pick your platform below:

First launch note: since this is independently distributed software, your operating system will show a one-time warning before it opens. On Mac, right-click the app and choose Open, then Open again in the dialog. On Windows, click More info then Run anyway. This only happens the first time.

How it works

Timecode entry works like setting a clock — type digits and they shift in from the right as HH:MM:SS:FF. Choose a frame rate at the top; drop-frame mode (shown with a semicolon before the frames, like ;02, instead of a colon) switches on automatically for 29.97 and 59.94, and can be toggled for custom rates too.

Add 1:00;00 to 1:00;02 and TC-100 correctly returns 2:00;02 — accounting for the drop-frame rule automatically, the same way a real broadcast deck would.