variance costs

There are various costs needed to know in the variances.

Budgeted cost = budgeted hours x standard rate
Actual cost = actual hours x actual rate

To calculate standard cost we have to calculate standard rate which is the per unit budgeted cost that is calculated as:
Standard rate = (budgeted cost / budgeted hours)

However, standard costs can be calculated in three of the following ways:

1) Standard cost is calculated with budgeted hours like this:
standard cost = budgeted hours x standard rate

2) Standard cost is calculated with actual hours like this:
standard cost = actual hours x standard rate

3) Standard cost is calculated with standard hours like this:
standard cost = standard hours x standard rate

Is that all correct? Please let me know if there is any mistake because it is really important for me to know.