Official figures — October 2026. These are the confirmed prices published by the Department of Mineral and Petroleum Resources (DMPR), effective Wednesday, 7 October 2026. Petrol 93 rose 312 c/l, petrol 95 rose 333 c/l, diesel 500ppm rose 284 c/l, diesel 50ppm rose 324 c/l and illuminating paraffin rose 358 c/l. The previous official prices took effect on 2 September 2026.
As a rule of thumb, a diesel generator uses about 0.24 litres of diesel per kVA per hour at full load, or roughly 0.3 litres for every kilowatt-hour it produces. Actual consumption varies by model and load, so treat these as estimates.
Diesel Consumption per kVA: current diesel price
Enter your own figures below. The results update as you type.
Prices are the official figures effective 7 October 2026. Diesel prices are wholesale, so enter the pump price you actually pay. Results are estimates.
| Diesel grade | Inland wholesale | Coastal wholesale |
| Diesel 50ppm | R32.80 | R31.93 |
| Diesel 500ppm | R31.95 | R31.08 |
These are wholesale prices. The pump price you pay will be higher and varies by station.
Estimated consumption by generator size
Estimates assume a power factor of 0.8 and 0.3 litres per kWh generated.
| Generator size | 50% load | 75% load | 100% load |
| 10 kVA | 1.2 L/h | 1.8 L/h | 2.4 L/h |
| 20 kVA | 2.4 L/h | 3.6 L/h | 4.8 L/h |
| 30 kVA | 3.6 L/h | 5.4 L/h | 7.2 L/h |
| 50 kVA | 6.0 L/h | 9.0 L/h | 12.0 L/h |
| 100 kVA | 12.0 L/h | 18.0 L/h | 24.0 L/h |
| 150 kVA | 18.0 L/h | 27.0 L/h | 36.0 L/h |
| 250 kVA | 30.0 L/h | 45.0 L/h | 60.0 L/h |
| 500 kVA | 60.0 L/h | 90.0 L/h | 120.0 L/h |
Small generators are usually less efficient than this and can use noticeably more per kVA (a 10 kVA set at 75% load may use about 2.5 litres an hour); large modern sets can use a little less. The manufacturer’s data sheet gives the tested figure for your model.
Running cost per hour
| Generator size | Litres per hour at 75% load | Cost per hour at R31.95 per litre |
| 10 kVA | 1.8 | R57.52 |
| 20 kVA | 3.6 | R115.04 |
| 50 kVA | 9.0 | R287.59 |
| 100 kVA | 18.0 | R575.19 |
| 250 kVA | 45.0 | R1,437.97 |
50ppm vs 500ppm diesel
Consumption is the same on either grade. Use the grade the generator manufacturer specifies; many modern engines require 50ppm.
Inland vs coastal diesel price
Inland wholesale diesel is 87.2 cents per litre above the coastal price, which adds about R15.70 per hour to the cost of running a 100 kVA set at 75% load.
Wholesale vs pump-price context
The costs above use the regulated wholesale price as a floor. Add your supplier’s margin, and delivery if you buy in bulk.
How the estimate works
Litres per hour = kVA × 0.8 × load × 0.3. A 50 kVA generator at 75% load delivers about 30 kW and uses about 9 litres an hour.
Calculator and fleet-use links
- Diesel generator fuel consumption calculator
- Diesel cost calculator
- Fleet diesel cost calculator
- Fuel cost calculator
- Fuel price increase calculator
- Diesel price South Africa
- Petrol price today
Frequently asked questions
How much diesel does a generator use per kVA?
Roughly 0.24 litres per kVA per hour at full load, as an estimate. Check the data sheet for your model.
Does running at low load save fuel?
It uses less fuel per hour but more per kWh produced, because engines are least efficient at low load.
When does the price change?
On the first Wednesday of every month. The current prices took effect on 7 October 2026 and the next adjustment is due on Wednesday, 4 November 2026.