How much sand is in a cubic meter of concrete?

Approximately 707-738 kg of sand would be used in 1m3 of concrete.

To see how this is calculated, see below:

To some extent this depends on the type of concrete, however for normal usage you would expect the concrete to be made by using 1 part cement, 2 parts dry sand, 3 parts course stone aggregate and 1/2 part water. NB those are weight rather than volume terms.

As such approximately 4/13ths of the 1m3 mass would be sand. Concrete has a density ranging from 2300 - 2400 kg/m3

As such 4/13ths of 2300 = 707kg

and 4/13ths of 2400 = 738 kg