Bandwidth Delay Product Calculator
Calculate bandwidth delay product (BDP) from link bandwidth and round-trip time to size TCP windows for long fat networks.
What Is Bandwidth Delay Product?
Bandwidth delay product (BDP) is the amount of data that can be in flight on a network path at once. It is the product of link capacity and round-trip time, usually expressed in bits. TCP needs a receive window at least this large or a long fat network will sit idle waiting for acknowledgments.
BDP Formula
$$BDP = B \times RTT$$\(B\) is bandwidth in bits per second and \(RTT\) is round-trip time in seconds. When bandwidth is in megabits per second and RTT is in milliseconds:
$$BDP_{\text{bits}} = B_{\text{Mbps}} \times RTT_{\text{ms}} \times 1000$$Example: a 220 Mbps path with 14 ms ping has \(220 \times 14 \times 1000 = 3{,}080{,}000\) bits, or 3.08 Mbit (0.385 MB) of pipe capacity.
Why TCP Window Size Matters
A sender waits for acknowledgments. If the window is smaller than BDP, the pipe never fills. Satellite, transoceanic, and other high-bandwidth high-latency links are classic long fat networks. Size the window (often in bytes: BDP / 8) so one TCP stream can use the full path.
Related tools: Bandwidth Calculator and Data Size Converter.
Frequently Asked Questions
What does BDP tell me in practice?
It is the volume of unacknowledged data the path can hold. Set the TCP window at least this large (in bytes) so throughput is not window-limited.
Is ping the same as RTT?
Ping is a common RTT measurement. It includes network delay and a little host processing. Use it as a practical estimate of round-trip delay.
Should I use bits or bytes?
BDP is defined in bits. Operating systems and socket APIs usually configure window size in bytes, so divide bits by 8.
Does BDP include packet loss?
No. It is a capacity times delay product. Loss, congestion control, and bufferbloat still affect real throughput.
When is BDP most important?
High bandwidth combined with high latency, such as satellite, cross-continent backbones, and fast Ethernet over long distances.
Related Tools
Shuffle Paragraphs
Moon Sign Compatibility Calculator
Cost of Capital Calculator
Kinetic Energy Chicken Cooker
Kite Calculator
K Factor Calculator
Perpetuity Calculator
Yield to Call Calculator
Sort Text Lines
Moment of Inertia Calculator
Rectangle Calculator
JSON-LD To Flattened
Convert Image To WebSafe Colors
Calorie Deficit Calculator
BASDAI Score Calculator
Private Savings Calculator
Scale Calculator
JSON to JSONLINE
Compression Ratio Calculator
Grams to fl oz Converter