Is there a meter that measures arduino current (small current) and calculates average current and gives results what battery i need for certain period of time for that consumption.... like battery for i year, battery for 2 year, battery for month and so .. ?
Any reasonable multimeter will do this. However there is a caveat - until the chip is in a low power
mode you'll need to use a higher current range on the meter. If you provide a switch to short out the
meter you can close that before changing ranges so it doesn't power-cycle the Arduino.
However if the current is a complex and rapidly changing quantity there's no substitute for a
real coulomb meter. An oscilloscope with a current probe and an integration function in its math
menu can also be used. Not so easy or cheap.
what about this?