Broadcast TV Specs
The numbers a broadcast master is checked against: formats and frame rates, loudness, legal video levels, safe areas and drop-frame timecode, from the ATSC and EBU documents.
As of October 2026. Networks add their own delivery specs on top of these; their spec sheet wins. The broadcast deliverables checklist covers the textless elements, stems and other files that go with the master.
Broadcast Systems
ATSC 1.0 (US, Canada, Mexico)
29.97 / 59.94
29.97 drop frame
1080i, 720p
−24 LKFS (A/85)
HD is 1920×1080 interlaced at 59.94 fields (29.97 frames) or 1280×720 progressive at 59.94, MPEG-2 video (A/53) with AC-3 audio (A/52). Film-rate 23.976 sources are carried too.
DVB (Europe and 50 Hz regions)
25 / 50
25 fps non-drop
1080i, 720p; 1080p50 on some services
−23 LUFS (R 128)
HD runs at 25 frames (1080i with 50 fields) or 50 progressive frames. 25 fps is a whole number, so timecode needs no drop frame.
ATSC 3.0 (NextGen TV)
23.976 to 120
Drop frame at 29.97 and 59.94
Up to 2160p
−24 LKFS (A/85)
HEVC Main 10 video up to 3840×2160 and 120 fps (100 fps in 50 Hz regions), SDR in BT.709 or HDR in PQ or HLG (BT.2100). Audio is AC-4 in North America, MPEG-H in South Korea. FCC rules for the move from ATSC 1.0 are changing, so check the FCC's current rules before planning a delivery around them.
Loudness: ATSC A/85 and EBU R 128
Both use the ITU-R BS.1770 meter, and LUFS and LKFS are the same unit. The difference is what gets measured: A/85 measures dialogue, R 128 the whole mix. The loudness standards guide goes deeper, and the loudness specs cheat sheet puts the targets on one page.
| Spec | Target | Measured on | Tolerance | True peak |
|---|---|---|---|---|
| ATSC A/85 (US) | −24 LKFS | Dialogue (the anchor element), over the whole program | About ±2 dB measurement tolerance; don't aim for either edge | Below −2 dBTP |
| EBU R 128 (Europe) | −23.0 LUFS | The whole mix, over the whole program | ±1.0 LU only where the target isn't practical, e.g. live; ±0.2 LU for QC measurement | −1 dBTP maximum |
- • In the US, the FCC's CALM Act rules (47 CFR 73.682(e)) require stations to follow A/85 for commercials.
- • A/85:2026-07 adds a streaming annex. It recommends one target for everything on a service, somewhere between −23 and −27 LKFS.
- • Netflix and other streamers publish their own targets; see the loudness targets list.
Legal Video Levels (EBU R 103)
R, G, B and luma should stay inside the nominal range. R 103 tolerates small excursions up to the preferred limits, −5% to 105%, and an out-of-gamut warning should trip only when errors cover more than 1% of the picture. Nothing may go beyond the total range.
| Bit depth | Nominal (0–100%) | Preferred min/max | Total signal range |
|---|---|---|---|
| 8-bit | 16–235 | 5–246 | 1–254 |
| 10-bit | 64–940 | 20–984 | 4–1019 |
| 12-bit | 256–3760 | 80–3936 | 16–4079 |
Broadcast Calculations
Drop-Frame Timecode
Keeps 29.97 and 59.94 timecode in step with the clock. The free timecode calculator counts drop frame correctly in your browser.
Problem:
29.97 fps runs 0.1% slower than 30 fps, so non-drop timecode falls 108 frames (3.6 seconds) behind the clock every hour.
Solution:
Drop frame skips frame numbers 00 and 01 at the start of every minute except minutes 00, 10, 20, 30, 40 and 50. At 59.94 it skips frame numbers 00 to 03. No pictures are dropped, only numbers.
Example:
01:00:59;29 → 01:01:00;02, but 01:09:59;29 → 01:10:00;00. One hour of 29.97 DF timecode = 107,892 frames.
Why It Matters:
A program timed in drop frame matches the station clock, so a 00:58:00;00 show really runs 58 minutes.
Commercial Lengths
Spots are counted in frames, not clock seconds
Problem:
A :30 spot is 30 seconds of timecode, but at 29.97 fps each timecode second lasts slightly more than a real second.
Solution:
Count frames: a :30 is 00:00:30:00, 900 frames. At 29.97 that plays for 30.03 seconds of clock time.
Example:
:15 = 450 frames, :30 = 900 frames, :60 = 1,800 frames at 29.97 fps
Why It Matters:
Traffic and automation systems schedule by timecode duration, so deliver spots to the exact frame count.
Safe Areas
Where action and graphics stay clear of the frame edge
Problem:
Some displays and downstream crops cut into the edge of the picture.
Solution:
Action safe is 93% of the width and height (3.5% in from each edge); graphics or title safe is 90% (5% in from each edge). EBU R 95 and SMPTE ST 2046-1 use the same figures.
Example:
1920×1080: title safe 1728×972; action safe about 1786×1004 (67 px and 38 lines in from each edge)
Why It Matters:
Keeps captions, lower thirds and key action inside the area every viewer sees.
Frequently Asked Questions
What loudness does US broadcast television use?
ATSC A/85 sets a target of −24 LKFS, measured on dialogue over the whole program with a BS.1770 meter, with true peaks kept below −2 dBTP. The FCC's CALM Act rules require US stations to follow A/85 for commercials.
What is the EBU R 128 loudness target?
EBU R 128 normalizes programs to −23.0 LUFS integrated loudness, measured over the whole mix, with a maximum true peak of −1 dBTP. A ±1.0 LU tolerance is allowed only where hitting the target is impractical, such as live programs. LUFS and LKFS are the same unit.
What is drop-frame timecode?
Drop-frame timecode skips frame numbers 00 and 01 at the start of every minute except every tenth minute, so 29.97 fps timecode keeps pace with the clock. At 59.94 fps it skips frame numbers 00 to 03. No frames of picture are removed.
What are the broadcast safe areas for HD?
Action safe is 93% of the frame and graphics (title) safe is 90%, centered. On a 1920×1080 frame, title safe is 1728×972 pixels.