The simple method
- List everything that will run at the same time.
- Add up the running power in kW.
- Divide by 0.8, the usual power factor, to get kVA.
- Add 20 to 25 percent headroom for motor starts and growth.
Typical loads
| Equipment | Running power |
|---|---|
| 1.5 ton split AC | about 1.8 kW |
| 5 ton spot cooler | about 6 kW |
| Package AC, 10 ton | about 12 kW |
| Industrial air cooler | about 0.5 kW |
| LED screen, per sqm | about 0.3 to 0.5 kW |
| PA system, medium event | about 3 to 5 kW |
| Catering: fryer, oven, warmers | about 10 to 25 kW |
| LED lighting for a 200 sqm tent | about 2 to 4 kW |
Worked examples
| Job | Load | Suggested generator |
|---|---|---|
| Garden event, 100 guests, lights, sound, 4 coolers | about 10 kW | 20 to 30 kVA |
| Villa with 8 split ACs and kitchen | about 25 to 35 kW | 45 to 60 kVA |
| 200 guest tented wedding with AC and catering | about 70 to 100 kW | 100 to 150 kVA |
| Site with cabins and tools | about 20 to 40 kW | 30 to 60 kVA |
| Tower crane | about 100 to 150 kW | 200 to 250 kVA |
Mistakes to avoid
- Forgetting motor start loads: AC compressors and pumps draw 3 to 6 times their running power for a second.
- Running a generator below 30 percent load for days, which causes wet stacking. Size it right, not huge.
- Ignoring three phase: large AC and catering equipment often need a three phase supply.
Send your equipment list to us and we size it free. Prices by size are on the generator price list.
Last updated 10 November 2026. Figures are typical for UAE conditions; we confirm sizing for every job.
