This calculator does not invent a universal fuel figure. Ask the supplier for the proposed engine model's fuel-consumption table first, then enter the applicable litres per hour.
Diesel generator fuel consumption calculator
Enter the litres-per-hour value for the exact engine and load point shown on the proposed supplier datasheet. Then add the actual operating schedule.
- 1. Enter verified L/hUse the exact engine model and expected load point.
- 2. Add your scheduleEnter running hours, operating days and local diesel price.
- 3. Compare the resultReview daily litres, monthly litres and estimated NGN cost.
Do not have a litres-per-hour figure yet? Review the 10kW planning guide for a clearly labelled estimate, or request model-specific fuel data before comparing suppliers.
Use real kW load, not generator kVA alone
Generator kVA identifies a rating range, but fuel is burned according to engine operation and actual electrical demand. A lightly loaded generator and a generator working near its rated output will not consume the same amount of diesel.
| Step | Data to use |
|---|---|
| 1. Build the load list | Record running kW and the starting method of the largest motor, pump, compressor or chiller. |
| 2. Select duty | State whether the generator is standby backup or prime/long-hour power. |
| 3. Confirm exact engine | Use an engine model number, not only a brand or a generic generator size. |
| 4. Match the load point | Use the supplier's litres-per-hour figure closest to the expected percentage load. |
| 5. Apply runtime | Litres per hour x operating hours gives daily consumption; multiply again by operating days. |
Evidence to request before accepting a fuel claim
A useful quotation should connect the fuel figure to the exact engine and generator configuration being offered.
- Exact engine make and model
- Prime and standby rating basis
- Fuel table at multiple load points
- Alternator and controller model
- Factory test scope for the ordered unit
- Written assumptions behind the calculation
What changes monthly generator operating cost
Fuel is only one part of generator operating cost. Service intervals, filters, oil, coolant, batteries and the consequences of running at very low or very high load should also be included in the buyer's comparison.
If your site runs for long hours, ask for prime-duty sizing and service recommendations. For a backup-only site, send the essential-load list and largest motor so the generator is not oversized simply by guesswork.
Calculate fuel use before requesting a generator price
After estimating runtime and fuel cost, open the relevant quotation page and send the actual load schedule. The kW figures below are planning conversions, not guaranteed usable site load.
| Quotation page | Planning conversion at 0.8 power factor | Important input |
|---|---|---|
| 10kW / 12.5kVA generator quote | 10kW is approximately 12.5kVA | Small business load list, fuel preference, phase and daily runtime. |
| 100kVA generator price Nigeria | Approximately 80kW | Hotel, school, office or commercial load plus the largest motor. |
| 250kVA generator price Nigeria | Approximately 200kW | Cold room, estate or factory load schedule and starting method. |
| 500kVA generator price Nigeria | Approximately 400kW | Detailed project load, duty, ATS, load-test and shipping scope. |
Request verified fuel data and a generator quote
Complete the known project details. WhatsApp will open with a structured request that the supplier can answer model by model.
Fuel consumption FAQ
How do I calculate diesel generator fuel consumption?
Use the proposed engine model's litres-per-hour figure at the expected load, then multiply it by daily running hours and operating days.
Why is there no universal litres-per-hour value for each kVA?
Fuel use changes with the engine model, actual load, duty rating, ambient conditions, maintenance and operating pattern.
What evidence should a generator supplier provide?
Request the exact engine model, a model-specific fuel table, rating basis and the available factory test scope.
