Free calculator
Estimate an iPhone video’s exported size.
Choose a duration and iMovie export resolution to calculate a realistic range from Apple’s published estimates.
Video details
Estimated exported size
Why this is a range
Video size is not determined by resolution alone. Duration, frame rate, codec, HDR, movement, detail, and the exporter’s bitrate all affect the result. Apple therefore publishes an approximate range for each iMovie export resolution instead of one guaranteed number.
This calculator multiplies those per-minute ranges by your duration. It does not predict the output of Video Compressor or promise a particular saving for your source video.
Apple’s published estimates
| Export resolution | Approximate size per minute |
|---|---|
| 1080p | 70–105 MB |
| 720p | 19–27 MB |
| 540p | 12–16 MB |
| 360p | 6–9 MB |
Source: Apple Support, “Compress a video on iPhone”, published July 29, 2026.
Frequently asked questions
How big is a 10-minute iPhone video?
Using Apple’s published iMovie export ranges, 10 minutes is about 700 MB to 1.05 GB at 1080p, 190 to 270 MB at 720p, 120 to 160 MB at 540p, and 60 to 90 MB at 360p.
Why does the calculator show a range instead of one number?
Duration, frame rate, codec, HDR, movement, and detail all change the exported size, so Apple publishes an approximate range per resolution rather than a guaranteed figure.
Does this predict what Video Compressor will save?
No. It uses Apple’s iMovie export estimates only. Video Compressor shows its own estimate before compressing and the measured result afterwards.
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