Aspect Ratio Calculator
What survives the crop when one master has to serve cinema, YouTube and Reels. The calculator above takes source resolution and target ratio and returns output resolution, crop amount and safe area — computed in your browser, with no sign-up and nothing leaving your device.
Aspect Ratio Calculator
- Output resolution
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- Discarded
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- Source ratio
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Runs entirely in your browser — no sign-up, nothing transmitted.
What the number actually depends on
Cropping UHD 16:9 to 9:16 leaves 1080 × 1920 — exactly Full HD, with 71 % of the frame discarded.
2.39:1 from a UHD sensor costs 25 % of the vertical pixels before any stabilisation.
The gap between a number that goes into a quote and one that holds on the day is rarely the formula — it is whether the constraints were entered honestly. That is why the inputs are spelled out below.
Common mistakes
The places where the arithmetic is right and the day still falls over:
- Deciding on vertical deliverables after the shoot
- Placing titles outside the 9:16 safe area in the master
In day-to-day production
Shooting with a 9:16 safe area marked on the monitor costs nothing and saves the reframe entirely.
The number belongs in post and review — the point where a decision is still free to change. Working it out on the shoot day is no longer calculating; it is finding out.
In TillyGen this is not a separate step: the result sits inside the plan itself, alongside the shot list, schedule and call sheet. Change a constraint and the dependent values move with it — the affected parts of the plan are flagged rather than quietly left behind.
Frequently asked
How accurate is the Aspect Ratio Calculator?
The maths is exact; the inputs rarely are. Treat the result as a solid floor and add your buffer deliberately rather than smuggling it into the inputs — a flattered input hides the buffer from everyone who plans with it later.
Is the calculator free?
No. It runs entirely in your browser, with no sign-up and nothing transmitted. There is no usage limit and no account.
Where does this fit in production planning?
In post and review. There it is a basis for deciding; later it is only a finding.
Can I export the result?
The calculator itself only displays the value. In TillyGen it lands directly in the shot list, schedule and call sheet, and goes out as PDF, CSV or through the API to everyone working from it.
What does the calculator return?
Output resolution, crop amount and safe area. The first value is the one you carry into the plan; the rest show how sensitively it reacts to the inputs.
What should I watch for in the result?
Mainly this: deciding on vertical deliverables after the shoot. That is the mistake that most often turns a correctly calculated number into one that does not hold.