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Developer tools·Networking

Bandwidth / Transfer Time Calculator

Calculate file download or upload time from size and Mbps, or find data volume from speed and duration. Supports metric and binary units. Free, instant.

Added Jun 1, 2026

Quick examples

Input

Result

Enter a value for calculate to see your result.

How it works

Calculates file transfer time from file size and connection speed, or the data volume transferred in a given time. Supports metric and binary units from bps through Tbps and bytes through TiB.

Formula

Time = (File size in bytes × 8) ÷ Speed in bps

bps
Bits per second (network speed is almost always in bits, not bytes)
× 8
Convert bytes to bits before dividing by bps

Step by step

  1. 01Choose transfer time or data volume mode.
  2. 02Enter connection speed in bps, Kbps, Mbps, Gbps, or binary variants.
  3. 03Enter file size (time mode) or duration (volume mode) with the matching unit.
  4. 04Read the estimated transfer time or total data moved.

Examples

500 MB at 100 Mbps

500 MB = 4 000 Mbit; at 100 Mbps that takes 40 seconds under ideal conditions.

Inputs

Calculate:
transfer_time
File size:
500
File size unit:
mb
Connection speed:
100
Speed unit:
mbps

Result

Result:
40 sec
Transfer time:
40 sec
Data volume:
476.84 MiB

100 Mbps for 1 hour

100 Mbps sustained for one hour moves about 42 GiB of payload (ideal, no overhead).

Inputs

Calculate:
data_volume
Duration:
1
Time unit:
hr
Connection speed:
100
Speed unit:
mbps

Result

Result:
41.91 GiB
Data volume:
41.91 GiB
Note: Real-world transfers are slower due to TCP overhead, latency, and protocol headers — treat results as theoretical best case. ISP speeds are advertised in Mbps (megabits); file sizes are usually in MB (megabytes) — this tool handles the bits/bytes conversion.

Related guides

Frequently asked questions

Why divide by 8 when calculating transfer time?

Network speeds are measured in bits per second (Mbps), but file sizes are in bytes (MB). One byte equals 8 bits, so you multiply file bytes by 8 before dividing by bps.

Why is my actual download slower than the calculator shows?

Real transfers include TCP/IP overhead, server limits, Wi-Fi contention, and protocol round trips. The calculator assumes 100% utilization of the quoted line rate.