What this calculator does
A twenty two kilometre commute does not feel expensive. Done twice a day, five days a week, at Nigerian pump prices, it quietly consumes a six figure sum every month, and almost nobody has added it up.
This calculator does. Enter the distance, your vehicle fuel consumption, the current pump price and how often you make the journey, and it returns the cost of a single trip, the cost per kilometre, and the monthly and yearly totals. If several people share the vehicle, it also splits the cost per person.
It is equally useful for one off decisions. Whether to drive to Ibadan or take a bus, whether a cheaper flat further out is genuinely cheaper, whether a job offer twenty kilometres away is worth what the commute will cost. All of those are fuel arithmetic dressed up as life decisions.
How the calculation works
Fuel consumption is expressed in two ways. Kilometres per litre tells you how far you travel on one litre, so higher is better. Litres per 100 kilometres tells you how much fuel a fixed distance consumes, so lower is better. The calculator accepts either and converts internally.
The litres used are the distance divided by kilometres per litre. Multiply by the pump price and you have the fuel cost. For a return trip the distance is doubled, and for a recurring journey the weekly figure scales to a month at 4.33 weeks and to a year at 52.
The most important input is your actual consumption, not the manufacturer figure. Nigerian driving conditions, heavy traffic, air conditioning, vehicle age and tyre pressure all push real consumption well above the published number, often by twenty to thirty per cent. Measure it yourself by filling the tank, noting the odometer, driving normally and seeing how much fuel it takes to refill.
The formula
Litres used = Distance travelled ÷ Kilometres per litre
Journey cost = Litres used × Price per litre
Converting: Kilometres per litre = 100 ÷ Litres per 100 km
Monthly cost = Journey cost × Journeys per week × 4.33
A worked example
A commute is 22 kilometres each way. The vehicle manages 9 kilometres per litre in real traffic conditions and fuel costs ₦950 a litre.
The return journey is 44 kilometres, using 4.89 litres, which costs ₦4,644. Over five commuting days that is ₦23,220 a week, about ₦100,545 a month and ₦1,207,440 a year in fuel alone.
Now compare that with a colleague living 8 kilometres away. Her return trip is 16 kilometres, using 1.78 litres at ₦1,689 a day, or ₦36,566 a month. The difference is close to ₦64,000 every month, which is ₦768,000 a year. That figure belongs in any conversation about whether a cheaper rent further out is actually cheaper.
Things worth knowing
Measure your real consumption
Fill the tank, reset the trip meter, drive as you normally do, then divide the kilometres covered by the litres it takes to refill. Nigerian traffic conditions commonly push real consumption twenty to thirty per cent above the manufacturer figure.
Fuel is not the full cost
Servicing, tyres, insurance, repairs and depreciation all scale with distance. A realistic all in cost per kilometre is often considerably more than the fuel figure alone, which matters when you are comparing driving against public transport.
Cost the commute before the rent
A flat that saves ₦300,000 a year in rent but adds twenty kilometres to a daily commute can easily cost more once fuel and time are counted. Run both options through this calculator before comparing the rents.
Small habits move the number
Correct tyre pressure, removing unnecessary weight, steady driving and avoiding long idling in traffic all improve consumption measurably. None of them is dramatic alone, and together they can shift a fuel bill by ten per cent.
Common mistakes to avoid
- Using the manufacturer fuel consumption figure instead of your own measured one.
- Entering one way distance and forgetting to select a return journey.
- Using an outdated pump price when prices have moved.
- Treating fuel as the total cost of driving and ignoring servicing and tyres.
- Comparing a driving cost against a bus fare without including parking and time.
- Forgetting that air conditioning and heavy traffic raise consumption significantly.
Frequently asked questions
How do I find my vehicle fuel consumption?
Is it cheaper to drive or take public transport?
Does air conditioning use much fuel?
Why is my consumption worse than the official figure?
How do I split fuel costs fairly?
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Further reading on this site
If this calculator was useful, these sections of the site go deeper into the same subject.
- Cost reports submitted by readers
- Careers and commuting decisions
- Salary guides and household budgeting
- All 38 free calculators and tools
A note on accuracy. This calculator is provided for general information and planning. It performs arithmetic on the figures you supply and does not constitute financial, legal, tax, medical or academic advice. Rates, rules, fees and institutional policies change, and your own circumstances may differ from the assumptions used here. Verify anything important with the relevant institution or a qualified professional before acting on it. See our full disclaimer for more.