What units does curl use for bandwidth?
According to the source code it is
kiB per second.
Here you can see the definition uses
1024 and not
/* The point of this function would be to return a string of the input data,
but never longer than 5 columns (+ one zero byte).
Add suffix k, M, G when suitable... */
static char *max5data(curl_off_t bytes, char *max5)
#define ONE_KILOBYTE CURL_OFF_T_C(1024)
#define ONE_MEGABYTE (CURL_OFF_T_C(1024) * ONE_KILOBYTE)
#define ONE_GIGABYTE (CURL_OFF_T_C(1024) * ONE_MEGABYTE)
#define ONE_TERABYTE (CURL_OFF_T_C(1024) * ONE_GIGABYTE)
#define ONE_PETABYTE (CURL_OFF_T_C(1024) * ONE_TERABYTE)
Here you can see the calculation is done in ms and then divided by
1000 to get seconds.
/* Calculate the average speed the last 'span_ms' milliseconds */
curl_off_t amount = data->progress.speeder[nowindex]-
if(amount > CURL_OFF_T_C(4294967) /* 0xffffffff/1000 */)
/* the 'amount' value is bigger than would fit in 32 bits if
multiplied with 1000, so we use the double math for this */
data->progress.current_speed = (curl_off_t)
/* the 'amount' value is small enough to fit within 32 bits even
when multiplied with 1000 */
data->progress.current_speed = amount*CURL_OFF_T_C(1000)/span_ms;