Diesel Generator Fuel Consumption Chart: Complete Guide with Calculator
How much diesel does a generator use per hour? An indicative, industry-average chart covering every standard rating from 5 to 1500 kVA at 25–100% load, plus a formula to estimate running cost. Not brand-specific ratings: always verify against the manufacturer's datasheet.
Rishabh Power Solutions Engineering Team · 1 April 2026 · 3 min
Quick Answer
As a broad industry average, a diesel generator consumes approximately 0.25–0.30 litres per kWh at 75% load, so a typical 100 kVA set uses about 15 litres/hour, costing roughly ₹1,300–₹1,400/hour at current diesel prices. These are generic, indicative figures only, not the rated consumption of any Rishabh Power Solutions generator or of any specific brand. Always confirm from the manufacturer's datasheet.
Fuel Consumption Chart: 5 kVA to 1500 kVA
Important, please read before using this chart: This is not a Rishabh Power Solutions fuel consumption rating chart, and it does not show the figures of any specific brand or model that we manufacture or sell. The values below are rough, generic estimates compiled from published industry averages across diesel generator brands, shared only to give a broad idea for initial deliberation. For the specific fuel consumption of any particular brand or model, always refer to the official product specifications (datasheet) of that particular brand.
| Generator (kVA) | kW (PF 0.8) | 25% Load | 50% Load | 75% Load | 100% Load |
|---|---|---|---|---|---|
| 5 | 4 | 0.5 L/hr | 0.8 L/hr | 1.1 L/hr | 1.5 L/hr |
| 10 | 8 | 0.8 L/hr | 1.3 L/hr | 1.8 L/hr | 2.5 L/hr |
| 15 | 12 | 1.2 L/hr | 1.8 L/hr | 2.6 L/hr | 3.5 L/hr |
| 25 | 20 | 2.0 L/hr | 3.0 L/hr | 4.0 L/hr | 5.5 L/hr |
| 50 | 40 | 3.5 L/hr | 5.5 L/hr | 7.8 L/hr | 10.5 L/hr |
| 62.5 | 50 | 4.3 L/hr | 6.8 L/hr | 9.6 L/hr | 13.0 L/hr |
| 75 | 60 | 5.0 L/hr | 8.0 L/hr | 11.3 L/hr | 15.3 L/hr |
| 100 | 80 | 6.5 L/hr | 10.5 L/hr | 15.0 L/hr | 20.5 L/hr |
| 125 | 100 | 8.0 L/hr | 13.0 L/hr | 18.5 L/hr | 25.0 L/hr |
| 200 | 160 | 12.5 L/hr | 20.5 L/hr | 29.0 L/hr | 40.0 L/hr |
| 250 | 200 | 15.5 L/hr | 25.5 L/hr | 36.0 L/hr | 49.0 L/hr |
| 500 | 400 | 30.0 L/hr | 50.0 L/hr | 71.0 L/hr | 97.0 L/hr |
| 750 | 600 | 44.0 L/hr | 74.0 L/hr | 105.0 L/hr | 143.0 L/hr |
| 1000 | 800 | 58.0 L/hr | 97.0 L/hr | 138.0 L/hr | 189.0 L/hr |
| 1500 | 1200 | 86.0 L/hr | 143.0 L/hr | 204.0 L/hr | 279.0 L/hr |
Disclaimer: The chart above is an approximate, indicative guide only. It is not the tested, published, or guaranteed fuel consumption of any Rishabh Power Solutions genset or of any brand we deal in, and it must not be read as a rating or performance commitment. Actual consumption varies with engine make and model, genset age, load profile, site altitude, ambient temperature, fuel quality, and maintenance. Before taking any decision, verify fuel consumption from the specific manufacturer's official datasheet, or ask our team for the exact specification sheet of the model you are considering.
How to Calculate Running Cost Per Hour
Running Cost (₹/hr) = Fuel Consumption (L/hr) × Diesel Price (₹/L)
Example: 100 kVA at 75% Load in Delhi
- Fuel (indicative industry average): 15.0 L/hr × ₹87.67/L = ₹1,315/hour
- 8 hours/day = ₹10,520/day
- 25 days/month = ₹2,63,000/month
Why Load Factor Matters
On the same indicative averages, running at 25% load burns 0.325 L per kWh, 30% more per unit than 75% load. If your generator consistently runs below 40% load, it's oversized. Consider downsizing to save 15–25% on fuel.
7 Factors That Affect Fuel Consumption
- Load level: optimal at 75%
- Engine condition: worn injectors increase consumption 10–20%
- Altitude: above 1,000m, engines lose ~3.5% power per 300m
- Temperature: above 40°C, expect 2–5% more consumption
- Fuel quality: use BS-VI grade diesel
- Maintenance: regular service saves 5–15%
- Load type: reactive loads with low power factor increase demand
Frequently Asked Questions
How much diesel does a 62.5 kVA generator consume per hour?
As a generic industry average, approximately 9.6 L/hr at 75% load. At Delhi diesel prices (₹87.67/L), that is about ₹841 per hour. Actual consumption differs by brand and model. Refer to the specific manufacturer's datasheet.
How many litres per hour does a 500 kVA generator use?
As a generic industry average, about 71 L/hr at 75% load, a monthly cost of roughly ₹12.4 lakh running 8 hours/day. Actual figures vary by brand and model. Refer to the specific manufacturer's datasheet.
Is it bad to run a generator at low load?
Yes. Running below 30% load causes "wet stacking": unburned fuel builds up, causing carbon deposits and engine damage.
Need Help?
Use our free kVA Calculator or request a quote. Call +91 9810145225.
Sources
- Hardy Diesel / FW Power / Generator Source fuel consumption charts
- Goodreturns / BusinessToday, Indian diesel prices (April 2026)
- Shakti Foundation, "Diesel Generators: Improving Efficiency in India"
Rishabh Power Solutions Engineering Team
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