Diesel generator(DG) sizing calculator:

DG capacity required depends on the various factors. below is the basic formula to calculate the DG capacity for linear loads. for non linear loads like motors, Air conditioner etc., kindly take starting demand/KVA instead of nominal demand.

Enter total demand load:


Enter diversity factor:


Enter power factor:


Enter DG loading factor:



DG capacity in KVA will be =

Standard DG ratings (Three phase, 50 Hz) available with the DG manufactures*:

640 KVA, 706 KVA, 825 KVA, 900 KVA, 1000 KVA, 1110 KVA, 1132 KVA, 1250 KVA, 1400 KVA, 1675 KVA, 1700 KVA, 1760 KVA, 1825KVA, 2000 KVA, 2250 KVA, 2500 KVA, 2750 KVA, 3000 KVA, 3500, 3750 KVA

*- Values shown above are of M/s Cummins Generator technologies, one of the reputed DG vendor and ratings offered by other manufactures may differ.

The rating of the DG is based on a particular altitude and ambient conditions and rating will derate ( decreased) due to increase in altitude and temperature above these values.

Flashback: Diesel Engine was invented by Rudolf Diesel, A German mechanical Engineer in year 1897. before invention of diesel engine, steam engine had been used.