I have a 110v circular volt and jigsaw equipment but there are no 110v sockets available at the house.

How do I compute for the transformer capacity?

Check the wattage of the saw, then get a portable generator capable of driving that wattage.

If you don't expect to run both at one time, multiply the larger amps of the 2 times 115 volts is a better figure. Then times 1.25 to give a margin. A 5 amp saw would be 5x115x1.25= 719. Look for a transformer larger than that. If you will be running both at once, add the amps and then multiply.