Audio Buffer Latency Calculator
Digital audio is processed in blocks of samples called buffers, and each buffer adds a delay equal to the time it takes to fill. This buffer latency is the dominant tunable delay in a recording or live setup: smaller buffers feel more responsive but load the processor harder. This calculator converts a buffer size in samples and a sample rate into one-way latency and a round-trip estimate in milliseconds, and shows the buffer duration in seconds. Use it to pick a buffer size that keeps monitoring latency below the audible threshold while staying within your computer's processing budget.
Buffer latency formula
One-way latency (ms) = buffer size / sample rate * 1000
Round-trip latency (ms) = 2 * one-way latency
Samples per millisecond = sample rate / 1000
The round-trip figure is the simple input-plus-output buffer estimate. Real systems add analog-to-digital and digital-to-analog converter delays and driver overhead, so measured round-trip latency is usually a little higher.
Worked example
A 256-sample buffer at 48,000 hertz: one-way latency = 256 / 48,000 * 1000 = 5.33 milliseconds, round-trip about 10.67 milliseconds. At 96,000 hertz the same buffer halves to 2.67 milliseconds one-way.
Buffer latency: frequently asked questions
What is audio buffer latency?
Buffer latency is the delay introduced because a digital audio system processes sound in blocks (buffers) rather than one sample at a time. A buffer of N samples at a sample rate of fs samples per second takes N divided by fs seconds to fill, which is the delay each buffer adds. Smaller buffers reduce latency but demand more from the processor.
What is the buffer latency formula?
Latency in milliseconds = buffer size in samples divided by sample rate in hertz, times 1000. At 48,000 hertz a 256-sample buffer gives 256 divided by 48,000 times 1000 = 5.33 milliseconds of one-way latency.
What is round-trip latency?
Round-trip latency is the total delay from input to output, which includes both an input buffer and an output buffer. A common estimate is twice the single-buffer latency, though real systems add converter and driver delays on top. This calculator shows both the single-buffer figure and the doubled round-trip estimate.
What buffer size should I use?
For live monitoring and recording, lower buffers (64 to 256 samples) keep latency below the roughly 10 millisecond threshold many players notice. For mixing, where latency does not matter, larger buffers (512 to 2048) ease processor load. Match the buffer to the task.
Official sources
- U.S. National Institute of Standards and Technology: nist.gov (time and sampling units).
- NIST Reference on Constants, Units, and Uncertainty: SI units.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.