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Costs and money , Maintenance and tyres , Know your car · Mis à jour le 2026-10-18

How to track your car expenses

Most owners have a rough idea what they spend on fuel and a vague sense that the car is expensive. Very few know the exact figure. Tracking your expenses is not complicated, and it pays back in several ways: you see where the money goes, you notice problems early, you can plan for big bills and you have proof of care when you sell. All you need is a consistent habit.

Why it is worth the effort

• Real cost. You find out how much the car costs per month and per kilometre, which is often higher than guessed.
• Early warning. A sudden rise in fuel use per distance can point to under-inflated tyres, a dragging brake or an engine fault.
• Planning. Knowing when the next service, tyres or inspection fall due lets you save for them.
• Decision making. When repair bills pile up, your records help you decide whether to keep or replace the car.
• Resale. A complete history of services and repairs raises buyer confidence. See the service book and how to prepare your car for sale.

What to record

Keep it simple. A short list of items is better than a long one you give up on.

1. Fuel or charging: date, amount, cost and the odometer reading. For petrol and diesel cars, fill the tank each time if you can, to calculate consumption.
2. Servicing and repairs: date, odometer, what was done, parts and labour cost, and where.
3. Tyres: purchase, fitting, balancing, seasonal changes and storage.
4. Insurance and taxes: the amounts and due dates.
5. Parking, tolls, washing and fines.
6. Accessories and extras.
7. Inspections and deadlines: when the next one is due.

Always note the odometer with each entry. It is what turns a pile of receipts into useful information, such as cost per kilometre.

Choose a method

The best method is the one you will actually use.

• A notebook in the glovebox. No technology, but easy to lose and hard to total.
• A spreadsheet. Flexible and easy to calculate with, but you need to type everything in and make your own formulas.
• A phone app or a logbook service. Quick entries and reminders. Our My Garage logbook is built for this: cars, fuel, mileage, repairs, deadlines and costs in one private place.
• A folder for receipts. Whatever else you do, keep invoices for services and repairs. They are proof when you sell, and for warranty claims.

Build the habit

Enter fuel when you fill up, while the receipt is in your hand. Put service and repair entries in on the day you collect the car. Once a month, spend five minutes checking that nothing is missing. Take a photo of every receipt with your phone as a backup. Habit matters more than detail: a small number of regular, complete entries beats a perfect system you abandon after two weeks.

Calculate what matters

Consumption

Fill the tank, note the odometer, and next time fill again and note the amount. Divide the fuel added by the distance driven to get consumption for that period. Single readings vary, so look at the average over several fills. A clear rise with no change in how you drive is worth investigating. Our guide on saving fuel lists common causes.

Cost per kilometre

Add all costs over a period, including fixed costs such as insurance and taxes, and divide by the kilometres driven. This is the most honest figure of what each trip costs. For a quick look at a single journey use the trip cost tool.

Monthly average

Divide yearly costs by twelve to see what to set aside. This is useful for a budget, for which the real cost of owning a car gives a full list of items.

Use the numbers

After a few months, look for patterns. Is fuel the largest item? Are small repairs frequent? Is one trip type very costly? Compare your real figures with the estimate in the cost of ownership tool. Where you spend more than expected, look at the options in cheaper running costs.

Also use the records to plan ahead. If your tyres were fitted two years ago, or the last timing component was changed a long time ago, you can prepare for the bill before it arrives. See how often to service.

Keep your data private

Your records contain your habits, locations and sometimes the registration number or VIN. Keep them in a place you control. When you share records with a buyer, show only what is useful, such as the service history, and leave out personal details.

What to remember

• Record every fuel stop, service, repair and fixed cost, with the odometer reading.
• Choose a method you will actually use, and keep the receipts.
• Work out cost per kilometre and monthly average.
• Watch for changes in consumption as an early warning.
• Good records help you plan, save and sell.

Beginner Checklist Costs Fuel Service history Tyres