Tech calculators
Data, internet and technology tools — file sizes, transfer times and unit conversions.
Download-time calculator
Best-case transfer time from decimal file size and measured Mbps, with bit/byte and GiB caveats.
Upload-time calculator
How long an upload will take.
File-transfer-time calculator
How long a local file transfer will take.
Mbps to MB/s converter
Convert megabits to megabytes per second.
GB/MB/TB converter
Convert between megabytes, gigabytes and terabytes.
Video file-size estimator
Estimate a video's file size.
Audio file-size estimator
Estimate an audio file's size.
Bitrate calculator
Hit a target file size for a given duration.
Screen & image PPI calculator
Pixel density from resolution and diagonal — compare monitors, laptops and phones.
Data-usage calculator
Project daily usage to weekly/monthly.
Bits, bytes and transfer times
Connection speeds are quoted in megabits per second (Mbps), while file sizes are shown in megabytes (MB). There are 8 bits in a byte, so a 100 Mbps connection moves at most about 12.5 MB per second. The Mbps to MB/s converter does this step on its own.
Decimal and binary units
Storage makers usually count 1 GB as 1,000,000,000 bytes, while some operating systems count in powers of 1,024. That is why a new drive can appear smaller than advertised. The GB/MB/TB converter explains the difference between the two conventions.
Real speeds are lower than headline speeds
Wi-Fi, network congestion, protocol overhead and the server at the other end all reduce throughput. Download and upload time results are best-case figures at the speed you enter — use a measured speed test result for a realistic estimate.
Media file sizes depend mainly on bitrate: see the bitrate calculator and the video and audio file-size estimators.