Audio Latency Calculator
Two buffers of 256 samples at 48,000 Hz add about 10.67 ms of delay.
Quick answer: Multiply the buffer size by the number of buffers, divide by the sample rate and multiply by 1,000. For example, 256 samples x 2 buffers at 48,000 Hz is 10.667 ms, 128 samples x 2 buffers at 48,000 Hz is 5.333 ms and 512 samples x 3 buffers at 44,100 Hz is 34.83 ms.
The audio latency formula
Buffer latency in milliseconds equals samples times buffers, divided by the sample rate, times 1,000.
Each extra buffer adds one more buffer length of delay.
Take 256 samples x 2 buffers at 48,000 Hz. 256 × 2 ÷ 48,000 × 1,000 gives 10.667 ms.
Take 128 samples x 2 buffers at 48,000 Hz. 128 × 2 ÷ 48,000 × 1,000 gives 5.333 ms.
Buffers add up
Audio latency is the time from when a signal enters a system until it exits. It includes converters, drivers, sample rate, buffer size and delay in effects (MathWorks: Measure audio latency).
This page counts only the buffers. The more buffers you chain, the more delay you add.
How to convert audio latency step by step
- Read the buffer size in samples, the number of buffers and the sample rate.
- Multiply the samples by the buffers.
- Divide by the sample rate and multiply by 1,000.
- Read the total samples in the last column.
Example 1: 256 samples x 2 buffers at 48,000 Hz
- Start with 256 samples x 2 buffers at 48,000 Hz.
- 256 × 2 ÷ 48,000 × 1,000 = 10.667.
- The buffer latency is 10.667 ms.
256 samples x 2 buffers at 48,000 Hz = 10.667 ms
Example 2: 128 samples x 2 buffers at 48,000 Hz
- Start with 128 samples x 2 buffers at 48,000 Hz.
- 128 × 2 ÷ 48,000 × 1,000 = 5.333.
- The buffer latency is 5.333 ms.
128 samples x 2 buffers at 48,000 Hz = 5.333 ms
Example 3: 512 samples x 3 buffers at 44,100 Hz
- Start with 512 samples x 3 buffers at 44,100 Hz.
- 512 × 3 ÷ 44,100 × 1,000 = 34.83.
- The buffer latency is 34.83 ms.
512 samples x 3 buffers at 44,100 Hz = 34.83 ms
The three examples below use common sizes.
Each one shows the sum in full.
audio latency conversion table
| Buffers and sample rate | Buffer latency (ms) | Total samples buffered |
|---|---|---|
| 64 samples x 2 buffers at 48,000 Hz | 2.667 ms | 128 samples |
| 128 samples x 2 buffers at 48,000 Hz | 5.333 ms | 256 samples |
| 256 samples x 2 buffers at 48,000 Hz | 10.667 ms | 512 samples |
| 512 samples x 2 buffers at 48,000 Hz | 21.333 ms | 1,024 samples |
| 1,024 samples x 2 buffers at 48,000 Hz | 42.667 ms | 2,048 samples |
| 128 samples x 2 buffers at 44,100 Hz | 5.805 ms | 256 samples |
| 256 samples x 2 buffers at 44,100 Hz | 11.61 ms | 512 samples |
| 256 samples x 3 buffers at 48,000 Hz | 16 ms | 768 samples |
| 64 samples x 3 buffers at 48,000 Hz | 4 ms | 192 samples |
| 512 samples x 3 buffers at 44,100 Hz | 34.83 ms | 1,536 samples |
| 128 samples x 2 buffers at 96,000 Hz | 2.667 ms | 256 samples |
| 256 samples x 2 buffers at 96,000 Hz | 5.333 ms | 512 samples |
The highlighted row is the default of the calculator. The last column gives samples.
A quick mental shortcut for audio latency
At 48,000 Hz, every 48 samples last 1 ms. So 512 samples in total last about 10.67 ms.
Double the buffers and the latency doubles.
Worked examples
Two buffers of 128 samples at 48,000 Hz add about 5.333 ms. Two buffers of 64 samples add about 2.667 ms.
Three buffers of 256 samples at 48,000 Hz add 16 ms, and three buffers of 64 samples add 4 ms.
Different sample rates
Two buffers of 256 samples add about 11.61 ms at 44,100 Hz and about 10.67 ms at 48,000 Hz.
Generally, latency is lower for higher sampling rates (MathWorks: Measure audio latency).
What this page leaves out
Converters, drivers and effects add delay of their own, so the real round trip is longer than the buffer figure.
A loopback test, where you play a sound out and record it back, shows the real total. The measured value is the lower bound for what a microphone and loudspeaker will add to (MathWorks: Measure audio latency).
Reading the result
Many people notice delay once it grows beyond a few milliseconds when they play and monitor at once. How much matters depends on the player and the sound.
Treat the figure as a guide, not a rule.
Quick conversion answers
| Conversion | Result |
|---|---|
| 256 samples x 2 buffers at 48,000 Hz | 10.667 ms |
| 128 samples x 2 buffers at 48,000 Hz | 5.333 ms |
| 512 samples x 3 buffers at 44,100 Hz | 34.83 ms |
| 64 samples x 3 buffers at 48,000 Hz | 4 ms |
Where this conversion is used
Musicians pick buffer settings for recording and monitoring.
Engineers estimate the buffer part of a delay budget.
Common mistakes to avoid
- Counting one buffer. Multiply by the number of buffers.
- Treating it as total delay. Converters and drivers add more.
- Using the wrong sample rate. Check the project and the interface.
- Forgetting the 1,000. The answer would be in seconds.
Related converters
More buffer setups
32 samples x 2 buffers at 48,000 Hz is 1.333 ms. 48 samples x 2 buffers at 48,000 Hz is 2 ms. 96 samples x 2 buffers at 48,000 Hz is 4 ms.
192 samples x 2 buffers at 48,000 Hz is 8 ms. 384 samples x 2 buffers at 48,000 Hz is 16 ms. 768 samples x 2 buffers at 48,000 Hz is 32 ms.
160 samples x 2 buffers at 44,100 Hz is 7.256 ms. 320 samples x 3 buffers at 44,100 Hz is 21.77 ms. 640 samples x 2 buffers at 96,000 Hz is 13.33 ms.
Doubling the first number
64 samples x 2 buffers at 48,000 Hz is 2.667 ms. 96 samples x 2 buffers at 48,000 Hz is 4 ms. 192 samples x 2 buffers at 48,000 Hz is 8 ms.
384 samples x 2 buffers at 48,000 Hz is 16 ms. 768 samples x 2 buffers at 48,000 Hz is 32 ms. 1,536 samples x 2 buffers at 48,000 Hz is 64 ms.
320 samples x 2 buffers at 44,100 Hz is 14.51 ms. 640 samples x 3 buffers at 44,100 Hz is 43.54 ms. 1,280 samples x 2 buffers at 96,000 Hz is 26.67 ms.
Frequently asked questions
How do I calculate buffer latency?
Multiply samples by buffers, divide by the sample rate and multiply by 1,000.
What is the latency of two 256 sample buffers at 48 kHz?
About 10.67 ms.
What is the latency of two 64 sample buffers at 48 kHz?
About 2.667 ms.
Does it include converters and drivers?
No. They add more delay.
How do I measure the real round trip?
Play a sound out, loop it back and record it, as in a loopback test.
Does a higher sample rate help?
Yes, for the same buffer size.
Sources
- MathWorks: Measure audio latency (mathworks.com)
