ToolnozaFuel use and runtime formulas
Fuel used = fuel consumption rate × operating time. If a generator uses litres per hour, multiply L/h by hours to get litres. Estimated runtime = usable tank fuel ÷ fuel consumption rate. Keep the rate and tank volume in matching units.
Worked example
At a measured rate of 1.5 L/h, six hours of operation uses about 1.5 × 6 = 9 L. A tank with 15 L of usable fuel would run about 15 ÷ 1.5 = 10 hours at that same rate.
Fuel rate changes with load
Manufacturers may report consumption at a specified load. Actual use depends on the connected equipment, engine condition, fuel type, maintenance and environment. Use a rate measured at a similar load; do not treat a full-load rating as a precise estimate for every job.
Frequently asked questions
Does the estimate include reserve fuel? No; subtract any reserve from usable tank capacity. Can runtime be constant at every load? No, consumption changes with load. What should I use for critical planning? Manufacturer data and a safely measured rate under representative conditions.