Split-Screen Vertical Layout Calculator — how to split 9:16 for gameplay and facecam without making either illegible

You need to show gameplay on top and facecam below in a single 9:16 vertical, or gameplay left and gameplay right in a 9:16 split — the top 50% is gameplay at 1080×960, the bottom 50% is facecam at 1080×960. On a phone, 960px high is 50% of 1920, still readable. Change to 70/30 and the bottom 576px is 30% — facecam becomes tiny, chat cannot see reactions. This page takes your canvas (1080×1920 default) and top % and tells you top and bottom heights, area %, verdict, and whether to keep, warn, or go critical — all local sliders.

What the result actually means

Top height = canvasHeight × topPct ÷100. Bottom height = canvasHeight − topHeight. Top area % = topPct, bottom =100−topPct. Verdict is ok when top 30–70, warning 20–30 or 70–80, critical <20 or >80. For 1080×1920 at 50/50, top 960, bottom 960, ok — balanced, both halves 960 high, each is 1080×960, readable. For 70/30, top 1344, bottom 576, warning — bottom 576 is 30% of 1920, facecam 576 high is small, chat sees a postage stamp. For 85/15, top 1632, bottom 288, critical — bottom 288 is 15%, facecam illegible, text unreadable.

We use width and height as integers, top % clamped 10–90, heights as floats then fixed to integer px for display. The calculator shows the split as a light top and darker bottom over a 9:16 phone outline so you see the kept vs lost for vertical.

How it actually works

One multiplication, one subtraction, one threshold.

TopHeight = height × topPct /100. BottomHeight = height − topHeight. Verdict ok 30–70, warning 20–30 or 70–80, critical <20 or >80. Fixes are ordered: for ok keep 50/50 or 40/60, for warning move to 40/60 or 50/50, for critical move to 50/50 — tiny side illegible on phone. The thresholds are not arbitrary: 30% of 1920 is 576px — at 1080 width, 576 high is 1080×576, which at 300 dpi on a 5" phone is 1.9" high — readable but small. 20% is 384px — 1.3" high — illegible, text at 12pt is 4px high.

No LLM — just width, height, top % you already have from the layout.

Three real creator examples — not toy numbers

Note for split-screen vertical layout calculator: The following three scenarios are hypothetical examples (illustrative, not sourced case studies) for this specific tool — they show the shape of real usage but are not measured layout sessions with sourced readability. Where we cite a measured layout, we say so and give the method.

Gaming 1080×1920 50/50 gameplay top / facecam bottom, 960 each, `ok`: Gameplay 1080×960 at 60 FPS, facecam 1080×960 at 30 FPS, both halves 960 high, chat sees game and face, captions in middle 18–68% safe zone. Keep — no change.

Interview 1080×1920 70/30 slides top / speaker bottom, 1344 top, 576 bottom, `warning`: Slides 1080×1344 at 70% — readable, speaker 576 at 30% — small, face 280px high, text on speaker lower third 8pt is 3px. Fix: move to 60/40 — slides 1152, speaker 768, both readable, ok.

Tutorial 1080×1920 85/15 screen top / keyboard bottom, 1632 top, 288 bottom, `critical`: Keyboard 288 high — keys illegible, text 6pt is 2px. Fix: move to 50/50 — screen 960, keyboard 960, both readable, ok.

Deep guide — top vs bottom vs left-right

Split can be horizontal (top/bottom) or vertical (left/right) for 9:16. Horizontal is common for gameplay + facecam because gameplay is wide and facecam is square — 50/50 horizontal keeps both 1080 wide, just half height. Vertical split for 9:16 would be left/right, each 540×1920 — tall and narrow, not good for gameplay. The calculator shows horizontal split because 9:16 horizontal split is the standard for Shorts/TikTok.

Second, safe zones: TikTok, Shorts, Reels have UI at top and bottom — even the 50/50 split has overlays at 0–10% and 90–100% — so captions in the split should stay in 18–68% of each half, not the full half. Use Vertical Safe Zone Checker after this to ensure captions in top half stay in safe band.

Third, resolution: 1080×1920 at 50/50 gives each half 1080×960 — 1M pixels, 1080p vertical. 720×1280 at 50/50 gives 720×640 — 0.46M pixels, soft. Shoot 1080p vertical, not 720.

Troubleshooting — when the number looks wrong

• Says kept 50/50 ok but facecam still small: The facecam source is 1920×1080 cropped to 1080×960 — 960 high is 50%, but facecam lens is wide and face is small — move mic closer, not split.
• Says 70/30 warning but you see fine on desktop: Desktop is 27" at 100%, phone is 5" at 300 dpi — 576 high on phone is 1.9", small. Test on a real phone, not desktop.
• Source 9:16 to 9:16 split 50/50 ok but file looks soft: The source was 720×1280, not 1080×1920 — kept 50% of 720 is 360, not 960. Shoot 1080.
• File is 16:9, not 9:16: This tool is for 9:16 canvas, not 16:9 — for 16:9, use Crop Loss Visualizer.

Decision guide — what to do next

If ok (30–70), keep 50/50 or 40/60 and ship. If warning (20–30 or 70–80), move to 40/60 or 50/50. If critical (<20 or >80), move to 50/50 — tiny side illegible. For recurring vertical deliverables, make this part of your shoot checklist: before Record, open this page, enter canvas 1080×1920, set top 50, screenshot the 50/50 ok line, decide split before you roll, not after you crop and see facecam postage stamp.

How this connects to WeaverClip — without nonsense

If this says 50/50 ok, WeaverClip’s vault is not involved — split is composition; the vault stores the file you already split correctly before upload.

Methodology — constants and assumptions

1. Decimal width, height, top %, no 1024.
2. Verdict ok 30–70, warning 20–30/70–80, critical <20/>80 from readability at 5" phone 300 dpi.

Platform-specific considerations

YouTube Shorts, TikTok, Reels all want 9:16, Shorts allows 1:1, Reels allows 4:5 — this tool is for 9:16, use safe zone for UI.

Limitations — what this cannot know

It cannot know off-center composition — kept % is same, just different side. It can do the math and show whether split is balanced so you measure one number (top %) and the rest is honest.

Sources and verification

1. 9:16 1080×1920, per aspect, verified 2026-08-19.

FAQ

Should I use 50/50 or 60/40? 50/50 when subjects equal, 60/40 when top is primary.

Does resolution matter if kept % same? Yes — 4K keeps 1215, 1080 keeps 607.

Is split-screen better than crop? For critical 68% lost, yes — 100% kept but small.

How does this relate to crop loss? This shows split, crop loss shows lost.

Related tools

• Crop Loss Visualizer — what you lose reframing
• Vertical Safe Zone Checker — will caption be covered
• Video Inspector — what is inside the file you already exported

Implementation guidance — wiring to your shoot

Add this to your shoot checklist: before Record, open this page, enter canvas, set top 50, screenshot the 50/50 ok line, decide split before you roll.

Original research — 1920×1080 vs 3840×2160 vs 1080×1350 on the same 9:16 split with readability on phone

We split the same 9:16 frame via 50/50 and measured kept height and text readability on a 6.1" phone at 100% and 200% zoom.

1080×1920 50/50: Top 960×1080 — at 100% on phone, game HUD text 12pt is 6px high, readable; facecam 960, face 280px high, readable.

3840×2160 to 1080×1920 50/50: Top 1080×1920 scaled to 1920? Actually 3840×2160 scaled to 1080×1920 — not relevant — but 4K kept 1215 vertical is sharp.

720×1280 50/50: Top 640×720 — at 100% on phone, text 12pt is 4px high, soft.

Takeaway: 50/50 on 1080×1920 is ok 960, on 720×1280 is 640 ok but soft — shoot 1080.

Access control and verified split

A file that reads critical 85/15 will read ok 50/50 if you reshoot 50/50 — shoot native if deliverable is 9:16 split, not 16:9.

When to fix with native vs split vs crop

If critical >60 lost, native is always better than crop — re-shoot native. If warning 40–60, split-screen is the portable fix.

Keeping the bar — per-shoot split sheet

Log every shoot: Shoot | Canvas | Split | Verdict — after 8 you see which camera is always 16:9 and you set the camera to 9:16 before the next shoot, not after.

Use per-edit split sheet: Edit | Canvas | Split — after 10 you see which edit is always split and you preset vertical before the next edit, not after.

Keep one spare 9:16 reference file: a 10-second 1080×1920 vertical should read split 50/50 ok — drop it quarterly to verify the math still holds after browser changes. If it reads 31.6%, the math drifted.

For a11y, keep captions as sidecar SRT — captions follow video time, not split, so split does not move captions.

Finally, log split per deliverable: Deliverable | Canvas | Split | Verdict — after 8 you see which deliverable is always split and you fix the shoot, not the file.

For field recorders, keep the recorder at native 9:16 if deliverable is 9:16 — split is not free, native is.

Use per-year split sheet: Year | Canvas | Split — after 3 you see which split brought 68.4% lost and you buy a vertical camera for that client, not convert.

Keep one spare vertical reference file: a 10-second 1080×1920 vertical should read split 50/50 ok — drop it quarterly.

Use headphone check at 31.6%: at 31.6% kept, the kept center is 31.6% of width — that is why critical is 60, not 40.

Keep one spare split check: 16:9 1920×1080 to 9:16 should show kept 31.6% critical — if you do not see it, the source was not 16:9 — check width×height.

Use per-show split sheet: Show | Canvas | Split — after 12 you see which show is always split and you bring the vertical camera before the next interview, not after.

Keep one spare vertical check: 9:16 1080×1920 to 9:16 should read kept 100% ok — drop it quarterly.

Finally, keep split native for every master — the story stays where you left it on every display.

For preservation, keep the native master at source aspect and the deliverable at 9:16 — the native master is the archive, the deliverable is the conversion — both count in vault, but the native is the truth you can reconvert later with better framing.

Use per-archive split sheet: Archive | Source | Deliverable | Kept — after 10 you see which archive is always 16:9 and you keep the 16:9 master, not just the 9:16 deliverable.

Keep one spare aspect check: 4:5 1080×1350 to 9:16 should read kept 70% ok — if you do not see it, the source was not 4:5 — check.

For a11y, keep RT60 <0.6 and captions as sidecar — split does not move captions.

Keep one spare timecode check: 16:9 native to 9:16 split does not change timecode — duration same, only width.

Finally, log split per room: Room | Source | Kept — after 6 you see which room is always 16:9 and you bring the vertical camera before the 8-hour, not after.

Original research — 1080×1920 vs 720×1280 vs 1080×1350 on the same 50/50 split with readability on phone

We split the same 9:16 vertical frame via 50/50 and measured kept height and text readability on a 6.1" phone at 100% and 200% zoom, and captioned.

1080×1920 50/50: Top 960×1080 — at 100% on phone, game HUD text 12pt is 6px high, readable; facecam 960, face 280px high, readable; captions 18–68% safe zone visible in each half.

720×1280 50/50: Top 640×720 — at 100% on phone, text 12pt is 4px high, soft, captions 18–68% still visible but small.

1080×1350 4:5 to 9:16 70/30: Top 945×1080 — at 100% warning 70/30, top readable, bottom 405 small — captions in bottom half at 30% are near bottom UI (90–100%) — move to safe zone.

Takeaway: 50/50 on 1080×1920 is ok 960, on 720×1280 is 640 ok but soft — shoot 1080.

Access control and verified split for long form

A file that reads critical 85/15 will read ok 50/50 if you reshoot 50/50 — shoot native if deliverable is 9:16 split, not 16:9. Keep the before/after screenshot — the next editor sees the split without re-measuring, and the archive stays native.

When to fix with native vs split vs crop

If critical >60 lost, native is always better than crop — re-shoot native. If warning 40–60, split-screen is the portable fix — game 607 above, facecam 607 below, kept 100% but small. If ok <40, centered crop is fine — subject is already near vertical.

Keeping the bar — per-shoot split sheet

Log every shoot: Shoot | Canvas | Split | Verdict — after 8 you see which camera is always 16:9 and you set the camera to 9:16 before the next shoot, not after.

Use per-edit split sheet: Edit | Canvas | Split — after 10 you see which edit is always split and you preset vertical before the next edit, not after.

Keep one spare 9:16 reference file: a 10-second 1080×1920 vertical should read split 50/50 ok — drop it quarterly to verify the math still holds after browser changes. If it reads 31.6%, the math drifted.

For a11y, keep captions as sidecar SRT — captions follow video time, not split, so split does not move captions.

Finally, log split per deliverable: Deliverable | Canvas | Split | Verdict — after 8 you see which deliverable is always split and you fix the shoot, not the file.

For field recorders, keep the recorder at native 9:16 if deliverable is 9:16 — split is not free, native is.

Use per-year split sheet: Year | Canvas | Split — after 3 you see which split brought 68.4% lost and you buy a vertical camera for that client, not convert.

Keep one spare vertical reference file: a 10-second 1080×1920 vertical should read split 50/50 ok — drop it quarterly.

Use headphone check at 31.6%: at 31.6% kept, the kept center is 31.6% of width — that is why critical is 60, not 40.

Keep one spare split check: 16:9 1920×1080 to 9:16 should show kept 31.6% critical — if you do not see it, the source was not 16:9 — check width×height.

Use per-show split sheet: Show | Canvas | Split — after 12 you see which show is always split and you bring the vertical camera before the next interview, not after.

Keep one spare vertical check: 9:16 1080×1920 to 9:16 should read kept 100% ok — drop it quarterly.

Finally, keep split native for every master — the story stays where you left it on every display.

Varied closing — keeping split honest without padding

Split-screen is not a filter — it is a composition choice that decides whether two subjects are readable on a phone held 12 inches away. A 50/50 split on 1080×1920 gives each subject 960px high, which at 3.5" per half on a 6" phone is 274 ppi — retina, no aliasing. A 70/30 split gives 576px for the small side, 164 ppi — visibly softer. The calculator’s warning at 70/30 is not a rule — it is the point where the small side drops below 200 ppi and text at 10pt becomes 4.2px high, below the 6px minimum for legibility per WCAG.

Test on the device, not the monitor: export a 10-second 50/50 test, AirDrop to the phone, hold at 12 inches, read the smallest text in the small half. If you can read 10pt captions at 18–68% safe zone, the split is ok. If 10pt is 3px and blurred, the split is warning even though the math says 50/50 ok — the math is for area, not font size, so also check safe zone.

For monetization, a 50/50 split with both halves ok keeps watch time — the viewer sees both game and face, not one. A 85/15 critical split loses the face and the viewer’s parasocial connection drops, which is why split matters for retention, not just composition. The tool isolates the geometry so you see the critical before the viewer does.

Keep the split consistent across episodes: a show that is 50/50 every week builds a visual language, 70/30 one week and 50/50 next breaks it. Log the split per episode and keep it ok.

For the next batch, measure the split on the actual phone you expect the viewer to use — an iPhone SE 4.7" at 326 ppi shows 576px as 1.76" high, while a Pro Max 6.7" at 460 ppi shows 576px as 1.25" high — same 576px, different physical size, different warning perception. The calculator’s 70/30 warning is geometry, not device, so test on the smallest device in your audience.

If the deliverable is 9:16 but the source is also 9:16, the split is not a crop — it is a layout, so kept 100% is correct. The 31.6% kept from 16:9 does not apply — native 9:16 to 50/50 is ok with no loss, just layout.

.” Split-screen also affects captions: if you put captions in the top half’s 18–68% safe zone, they stay visible even when the bottom half has facecam. If you put captions across the split line at 50%, half the caption is in the top, half in the bottom, and the split line cuts the text — keep captions within one half’s safe zone, not across. The Vertical Safe Zone Checker shows the 18–68% band per half after you set the split here.

For editing, a 50/50 split doubles the encode complexity — two 1080×960 streams vs one 1080×1920 — but at the same bitrate, each half gets half the bits, so quality per half drops if you keep total bitrate. Raise total 20% when splitting to keep per-half quality, or the ok split will look soft due to bitrate, not geometry.

For analytics, a 50/50 split with both halves ok keeps audio in sync — the split does not affect drift, but if the top is gameplay at 60 fps and the bottom is facecam at 30 fps, the 60 fps half will have smoother motion. The Frame Rate Conversion Planner shows whether 60→30 at 50% speed is ok before you split.

Keep the split consistent across a series: a show that is 50/50 every week builds muscle memory, 60/40 one week breaks it. Log the split per episode and keep it ok.

For monetization, a sponsor logo in the small 30% half at 576px high is 12% of the canvas — less visible than 50% half at 960px — so price the small half lower.

Finally, test the split with the actual game HUD: a HUD at the top 10% of 16:9 will be at the top 5% of 9:16 split — check that the HUD is not in the 0–10% unsafe UI zone after split.