Audio file size from sample rate

This tool multiplies those four numbers with the closed relation file_bytes equals sample_rate times bit_depth times channels times duration divided by eight, then adds the forty-four-byte standard WAV header so the published file_bytes matches a canonical PCM WAV. Non-positive rates, unknown bit depths, illegal channel counts, and non-positive durations fail with invalid_input and are never billed.

How sample rate, bit depth, channels and duration become a file size

Bit depth is the number of bits stored per sample on each channel: eight, sixteen, twenty-four, or thirty-two for the widths this calculator accepts. Multiply sample rate by bit depth by channel count to obtain the bit rate in bits per second; divide by eight and multiply by duration to obtain the PCM payload in bytes. A canonical RIFF WAVE header for uncompressed PCM is forty-four bytes, so file_bytes equals that payload plus forty-four.

How to call the API and what the response contains

Send a JSON body with four required fields. sample_rate is a finite number of hertz from one to three hundred eighty-four thousand and also accepts the aliases sample_rate_hz, rate, sr, and hz. bit_depth is an integer from the closed set eight, sixteen, twenty-four, or thirty-two, also accepted as bits, bit_depth_bits, depth, or bits_per_sample. channels is an integer from one to thirty-two, also accepted as channel_count, num_channels, ch, or channel. duration is a strictly positive length in seconds at most eighty-six thousand four hundred (twenty-four hours), also accepted as duration_s, seconds, length, time, or duration_seconds. Missing fields, non-numeric strings, non-finite values, unknown bit depths, and out-of-range numbers return invalid_input and are never charged. On success the body echoes the rounded sample_rate, integer bit_depth and channels, duration_seconds and duration_minutes, samples_per_channel and total_samples, bytes_per_sample, bit_rate_bps and bit_rate_kbps, pcm_bytes, wav_header_bytes (always forty-four), file_bytes, IEC sizes size_kib and size_mib, SI sizes size_kb and size_mb, a size_human string, the formula, a short English message, and an ordered steps array you can recompute by hand. Pricing is a flat $0.002 per successful request with unit item.

Studio checkpoints, limits, and what this calculator is not

Studio checkpoints are easy to memorize: one minute of compact-disc stereo is about ten point zero nine mebibytes as a WAV; three minutes of forty-eight kilohertz twenty-four-bit stereo is fifty-one million eight hundred forty thousand PCM bytes; one hour of ninety-six kilohertz twenty-four-bit stereo is about one point nine three gibibytes. Prefer this capability when you already know the four PCM parameters and only need the byte count; if you need to convert hertz to kilohertz or samples per second, use a dedicated sample-rate unit converter instead. Keep the sample rate inside the published band so the product stays finite in IEEE double precision on the Worker and in the browser. Prefer sending JSON numbers rather than pre-formatted strings when you control the client; string numbers are accepted only when they match a strict finite numeric pattern. When teaching, pair a compact-disc happy path with a deliberate zero sample rate or a twelve-bit depth to demonstrate the hard invalid_input path. This landing targets people searching for an audio file size calculator from sample rate, an uncompressed WAV size estimator, or a PCM disk-budget tool. It is not a compressed MP3 or AAC bitrate calculator, not a sample-rate converter, not a real-time recorder, and not a container muxer for BWF, RF64, or CAF extras. Failed tasks that return invalid_input do not consume prepaid balance. Round-trip checks are straightforward: recompute sample_rate times bit_depth times channels times duration over eight, add forty-four, and confirm it equals file_bytes after nearest-byte rounding.