Instant answers. Zero fluff.
Every file size question,
answered in seconds.
Convert units, check platform limits, calculate media sizes — all client-side, all free.
Instant Unit Converter
Type a value, pick your units. Result appears instantly — no server, no waiting.
Quick Reference
| Value | Bytes | KB | MB | GB | TB |
|---|
Platform File Size Limits
Hit a limit? Get the exact cap and the fastest workaround — instantly.
Media Size Calculators
Estimate file sizes for video, audio, and images before you record or export.
Video File Size
Calculate size from resolution, bitrate & duration. Supports 720p to 8K.
PopularAudio File Size
MP3, WAV, FLAC — estimate size from bitrate and recording length.
NewImage File Size
RAW, JPEG, PNG, WebP — from resolution and color depth.
Storage Planner
How many photos, songs, or videos fit on your drive?
Transfer Time
How long to upload or download a file at a given speed?
Platform Limits Around the World
Major platforms enforce different file size limits by region and tier. Explore the landscape.
Markers represent platform HQ locations. Hover or tap for limit details.
Compression & Optimization Guides
Learn why your file is large and how to shrink it — without destroying quality.
Reduce PDF Size for Email
Strip metadata, downsample images, and use built-in OS tools to get under 25 MB.
VideoCompress MP4 Without Losing Quality
Use CRF encoding, HEVC, and smart resolution choices for dramatic size reduction.
ImageShrink JPEG File Size
Optimize quality settings, strip EXIF data, and convert to WebP for 60%+ savings.
DiscordCompress Video for Discord
Get your clip under 25 MB (or 500 MB for Nitro) with HandBrake or FFmpeg.
AudioReduce Audio File Size
Convert WAV to FLAC or MP3, choose the right bitrate, and trim silence.
WebOptimize Images for Web
Lazy loading, responsive srcsets, WebP/AVIF — a developer's checklist.
Complete Conversion Reference
Quick links to every conversion pair we support.
Bytes & Kilobytes
Terabytes & Petabytes
Bits & Data Rates
Frequently Asked Questions
How many KB in a MB?
There are 1,024 KB in 1 MB using binary (base-2) measurement, which is what operating systems typically use. In the decimal (SI) standard, 1 MB equals 1,000 KB. FileSize.org supports both modes in our converter.
How many MB in a GB?
1,024 MB make up 1 GB in binary. Storage manufacturers often use the decimal definition (1,000 MB = 1 GB), which is why a "500 GB" drive shows ~465 GB in your OS.
What is the difference between binary and decimal file sizes?
Binary uses powers of 1,024 (how computers actually address memory). Decimal uses powers of 1,000 (how manufacturers market storage). The difference grows at larger scales: a "1 TB" drive is actually ~931 GiB in binary.
What is the Discord file size limit?
Free Discord users can upload files up to 25 MB. Discord Nitro subscribers get up to 500 MB. Need to send a larger file? See our compress video for Discord guide.
What is the Gmail attachment size limit?
Gmail caps attachments at 25 MB per email. Files over this limit are automatically uploaded to Google Drive and shared as a link. Check our compress PDF for email guide for workarounds.
How do I calculate video file size?
Video file size = bitrate × duration. For example, a 10 Mbps video that's 60 seconds long is roughly 75 MB. Our video file size calculator handles all the math including audio tracks and container overhead.