Fuel Cost Per kWh Calculator

Work out fuel cost per kwh instantly with clear inputs, formula shown and shareable results.

About Fuel Cost Per kWh Calculator

Each litre of fuel contains its calorific value in megajoules, which divided by 3.6 gives kilowatt-hours of heat, and multiplied by conversion efficiency gives useful electrical kilowatt-hours. Fuel price divided by that figure gives the fuel cost per kilowatt-hour, to which maintenance must be added for a true comparison against grid tariffs.

Formula

Cost per kWh

kWh per litre = CV (MJ/L) / 3.6 x efficiency; cost per kWh = fuel price / kWh per litre + maintenance

Worked example

With the default values below, Fuel Cost Per kWh Calculator returns Total Cost Per kWh of $25.7105. Change any input above and every figure here is recalculated in your browser.

Inputs used

Fuel Priceminimum 0 per L: 92 per L
Net Calorific Valueminimum 0.01 MJ/L: 36 MJ/L
Conversion Efficiencyaccepts 1–100 %: 38 %
Maintenance Costminimum 0 per kWh: 1.5 per kWh

Results

Total Cost Per kWh: $25.7105
Fuel Cost Per kWh: $24.2105
Useful kWh Per Litre: 3.8000
Maintenance Share Of Cost: 5.83%

Step by step

1Values used
2Cost per kWh
3Total Cost Per kWh= 25.7105
4Fuel Cost Per kWh= 24.2105
5Useful kWh Per Litre= 3.8000
6Maintenance Share Of Cost= 5.83

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why is diesel generation so much dearer than grid power?

Because efficiency is around 38% against 45-60% for a modern combined cycle plant, and fuel is bought at retail. Diesel generation typically costs three to five times grid tariff.

Should capital cost be included?

For a genuine comparison, yes — add depreciation and financing per kilowatt-hour at the expected annual run hours. For a standby set used rarely, capital dominates the cost per unit generated.