About Bandwidth Calculator

Calculate bandwidth and transfer time requirements with user scaling analysis. Part of the DevTools Surf developer suite. Browse more tools in the Calculators collection.

Use Cases

• Estimate monthly cloud egress costs before architectural decisions
• Size internet connections for office or data center build-outs
• Calculate download times for large file transfers or software distributions
• Plan video streaming infrastructure bandwidth for expected concurrent viewers

Tips

• Enter concurrent users and average request/response size to calculate sustained bandwidth requirements at peak load
• Toggle between Mbps and GB/month units — ISP contracts are usually in Mbps while cloud egress pricing is in GB
• The user scaling chart shows how bandwidth grows non-linearly when multiple users download simultaneously

Fun Facts

• Netflix accounts for about 15% of all downstream internet traffic globally during peak evening hours — more than any other single application. A 4K HDR stream consumes up to 25 Mbps.
• The Shannon-Hartley theorem (1948) established the theoretical maximum data rate for a noisy channel. Modern fiber optics are approaching but have not yet reached this theoretical limit.
• The first transatlantic internet cable (TAT-8, 1988) had a capacity of 280 Mbps. Today, a single modern transatlantic cable (like 2Africa, landing in 2024) has a capacity of over 180 Tbps — a 640,000x increase in 36 years.

FAQ

What is the difference between bandwidth and throughput?

Bandwidth is the theoretical maximum data rate of a connection. Throughput is the actual rate achieved in practice, accounting for overhead, protocol inefficiency, retransmits, and congestion. Throughput is typically 70-90% of bandwidth.

How do I convert Mbps to GB per month?

Multiply Mbps by 3,600 (seconds/hour) x 24 (hours/day) x 30 (days) / 8 (bits/byte) / 1,000 (MB to GB). A sustained 1 Mbps link transfers about 324 GB/month.

Does gigabit internet mean I get 1GB/s download speed?

Gigabit internet is 1,000 Mbps = 125 MB/s in bytes. Maximum download speed is ~117 MB/s after overhead. Actual speeds depend on server capacity, your Wi-Fi connection, and the number of concurrent users on your household connection.