Free Video File Size Calculator
Calculate video file size from resolution, codec, bitrate, and duration.
What is a video file size calculator?
A video file size calculator is a free online tool that helps you estimate video file sizes from resolution, frame rate, bitrate, and duration. It runs entirely in your browser — no signup, no app, and no data is ever sent to a server.
A video file size calculator estimates the storage space needed for any video based on resolution, codec, frame rate, quality, and duration. Video files take up more space than most people expect — a 4K video at medium quality with H.264 requires about 15 GB per hour, while an 8K maximum-quality video can use over 200 GB per hour. The calculator supports H.264, H.265/HEVC, VP9, and AV1 codecs across all common resolutions.
How it works
The calculator uses per-codec, per-resolution bitrate tables at four quality levels, adjusted by frame rate factor (24fps = 0.8×, 30fps = 1.0×, 60fps = 1.6×). File size = (bitrate × 1,000,000 ÷ 8 × duration in seconds). Results are shown in GB for the full file and per hour for easy comparison.
When to use a video file size calculator
Before recording or rendering video to ensure you have enough storage space. When choosing between codecs for a project. When estimating upload times and bandwidth requirements for streaming. When planning storage for surveillance camera footage. When deciding on bitrate settings for video production, archival, or distribution.
Common mistakes when estimating video file size
The mistake I see most often is people confusing megabits with megabytes. A 100 Mbps bitrate is 12.5 MB/s, not 100 MB/s. That 8:1 ratio gets overlooked constantly, and the result is expecting files to be eight times smaller than they actually are. Another common error is forgetting that higher frame rates need proportionally more bitrate to maintain visual quality — a 60fps video at the same bitrate as 24fps will look noticeably worse because each frame gets less data.
Bitrate tables in many online calculators are also outdated. H.264 encoding at 1080p today produces better quality at 8 Mbps than it did at 12 Mbps five years ago because encoder software keeps improving. The calculator uses modern per-codec tables, but if you are working with a specific encoder like x265 or SVT-AV1, results will vary. For maximum compatibility, stick with H.264 — for maximum space savings on archived content, AV1 is the clear winner.
How codec choice affects your storage
The codec matters more than resolution in determining final file size. H.264 is the most compatible but uses the most space. H.265 (HEVC) cuts file sizes by roughly 40–50% at identical quality. VP9 is similar to H.265. AV1 is the most efficient — 30–50% smaller than H.264 — but encoding takes significantly longer and hardware support is still limited. For archival where storage is expensive, AV1 gives the biggest savings. For content that must play on the widest range of devices, H.264 is still the safest bet.
How to use this calculator
- Enter video details — Input resolution, frame rate, codec, and duration.
- Set quality preference — Choose low, medium, high, or maximum quality.
- Read the result — See estimated file size, bitrate, and storage needed for your video.
Frequently asked questions
How do I calculate video file size?
File size = bitrate × duration. For a 10-minute 1080p video at 10 Mbps: 10 Mbps ÷ 8 = 1.25 MB/s. 10 minutes × 60 = 600 seconds. 1.25 × 600 = 750 MB. Bitrate depends on resolution, frame rate, and codec efficiency. The calculator handles all codec-specific bitrate estimates.
What bitrate should I use for 1080p video?
Recommended bitrates: 1080p24 (8-12 Mbps H.264, 4-8 Mbps H.265, 3-6 Mbps AV1). 1080p60: 12-18 Mbps H.264, 6-12 Mbps H.265, 4-8 Mbps AV1. Higher bitrate = better quality but larger files. For streaming, use the lower end; for archival, use the higher end.
How much space does a 4K video take?
A 4K 24fps 10-bit video: H.264 at 35-50 Mbps = 4.4-6.3 MB/s = 15.8-22.5 GB per hour. H.265 at 20-35 Mbps = 11.3-19.7 GB per hour. AV1 at 15-25 Mbps = 6.7-11.3 GB per hour. ProRes (professional): 150-300 Mbps = 67-135 GB per hour.
What codec gives the smallest file size?
AV1 is currently the most efficient codec, offering 30-50% smaller files than H.264 at the same quality, and 20-30% smaller than H.265. VP9 (used by YouTube) is similar to H.265. H.264 is the most compatible but least efficient. HEVC/H.265 is a good middle ground between size and compatibility.
How does frame rate affect file size?
Doubling the frame rate roughly doubles the file size at the same quality (or requires lower quality per frame to keep the same bitrate). 60fps video is about 40-60% larger than 24fps video at the same resolution and quality setting. The calculator adjusts bitrate estimates for 24, 30, and 60 fps.
How does resolution compare to codec choice in determining file size?
Resolution quadruples pixel count from 1080p to 4K, which would suggest a 4× file size increase. In practice, codec efficiency improvements between H.264 and AV1 often offset resolution increases by 30–50%. A 4K AV1 file can be smaller than a 1080p H.264 file at similar quality, which surprises most people.