Generator converter & calculator
Professional conversion tools for generator buyers & engineers · kVA, kW, Amps, Fuel, Noise & more
| Load type | Typical PF |
|---|---|
| Resistive (heaters, lighting) | 1.0 |
| Motors / compressors | 0.7 – 0.85 |
| Commercial buildings | 0.8 – 0.9 |
| Data centers | 0.9 – 0.95 |
| kW | HP (approx) | Typical use |
|---|---|---|
| 3 kW | 4.0 HP | Home backup |
| 5.5 kW | 7.4 HP | Small workshop |
| 10 kW | 13.4 HP | Small business |
| 20 kW | 26.8 HP | Industrial light |
| Appliance | Running (W) | Surge (W) |
|---|---|---|
| Air conditioner 1HP | 750 | 2,250 |
| Air conditioner 1.5HP | 1,100 | 3,300 |
| Refrigerator | 150 | 600 |
| Washing machine | 500 | 1,500 |
| Water pump (0.5HP) | 375 | 1,125 |
| Microwave oven | 1,000 | 1,000 |
| LED lighting (set) | 60 | 60 |
| Electric drill | 600 | 1,800 |
| Angle grinder | 900 | 2,700 |
| Concrete mixer | 1,100 | 3,300 |
| Arc welder | 4,000 | 4,000 |
| Server rack (1U) | 500 | 500 |
| Region | Single | Three phase | Hz |
|---|---|---|---|
| China / EU / AU | 220–240V | 380–415V | 50 |
| USA / Canada | 120/240V | 208/480V | 60 |
| Japan | 100V | 200V | 50/60 |
| Middle East | 220–230V | 380–400V | 50 |
| Generator size | Typical breaker |
|---|---|
| 3–5 kW / 220V single | 20–30A |
| 8–10 kW / 220V single | 40–50A |
| 15–20 kW / 380V three | 30–40A |
| 30–50 kW / 380V three | 60–100A |
| Fuel type | Avg consumption | Energy density |
|---|---|---|
| Diesel | 0.27 L/kWh | 35.8 MJ/L |
| Petrol (gasoline) | 0.33 L/kWh | 32.0 MJ/L |
| LPG (propane) | 0.42 L/kWh | 25.3 MJ/L |
| Natural gas | 0.25 m³/kWh | 37.0 MJ/m³ |
| Generator type | @ 7m | @ 1m (est.) | Suitable for |
|---|---|---|---|
| Open frame petrol | 85–95 dB | 102–112 dB | Construction / outdoor |
| Open frame diesel | 88–98 dB | 105–115 dB | Heavy industrial |
| Inverter generator | 58–65 dB | 75–82 dB | Camping / events |
| Silent / canopy genset | 60–68 dB | 77–85 dB | Offices / hospitals |
| Type | Internal dimensions | Max payload | Usable CBM (90%) |
|---|---|---|---|
| 20GP | 5.9 × 2.35 × 2.39 m | 28,000 kg | 29.8 m³ |
| 40GP | 12.0 × 2.35 × 2.39 m | 26,500 kg | 60.8 m³ |
| 40HQ | 12.0 × 2.35 × 2.69 m | 26,500 kg | 68.4 m³ |
How to use the BISON generator calculator
BISON’s free generator sizing calculator covers power conversion, load sizing, amperage, fuel cost, noise, and CBM shipping — results in seconds.
1. Power converter
Convert between kVA, kW, HP, watts, and MW instantly. For kVA ↔ kW conversions, enter your power factor — use 0.8 as the standard default if unknown.
2. Load calculator
Add your appliances, set quantities, and click Calculate. The tool totals running watts and surge watts, applies a 25% safety margin, and recommends the right BISON generator model.
3. Current converter
Calculate output current (amps) from kW or kVA for single-phase or three-phase systems — essential for cable sizing and breaker selection.
4. Fuel & cost
Enter generator size, load percentage, and local fuel price to estimate hourly, daily, and monthly running costs for diesel, petrol, or LPG.
5. Noise level
Convert dB(A) readings between distances using the inverse square law — useful for noise compliance checks and generator placement planning.
6. Weight & size
Convert weight (kg ↔ lbs) and dimensions (mm ↔ inch), then calculate CBM and 20GP container fit for international FOB orders.
FAQs about generator calculator
What is the difference between kW and kVA?
kW is real power — what your equipment actually consumes. kVA is apparent power, which includes reactive load. The relationship is: kW = kVA × Power Factor. Generators are rated in kVA; most appliances are rated in kW, so this conversion is essential for correct sizing.
What power factor should I use?
Use 0.8 — the standard default for commercial and industrial applications, and the power factor at which most generators are rated. Resistive loads (heaters, lighting) use 1.0; motors and compressors typically range from 0.7–0.85.
How do I calculate what size generator I need?
Use the Load Calculator tab. Add all appliances, set quantities, and click Calculate. The tool applies a 25% safety margin and recommends a minimum generator size. Never run a generator above 80% capacity continuously — it causes overheating and shortens service life.
What is the difference between running watts and surge watts?
Running watts are a continuous draw. Surge watts (starting watts) is the peak power required when a motor starts — typically 2–3× the running load. Your generator must handle the surge, or it will trip at startup.
How much fuel does a diesel generator use per hour?
A 10 kW diesel generator at 75% load consumes approximately 2.0 L/h. Use the Fuel & Cost tab to calculate exact consumption based on your generator size, load percentage, and local fuel price.
What does CBM mean in generator shipping?
CBM (Cubic Metre) is the standard freight volume unit for container shipping. It determines whether your order fits a 20GP, 40GP, or 40HQ container and directly affects freight cost. Use the Weight & Size tab to calculate CBM and container fit for international FOB orders.