Petrol vs Diesel Cost Calculator
Petrol vs diesel cost calculator compares total running costs between gasoline and diesel vehicles. Find which fuel type saves more money based on your driving distance, fuel efficiency, and local prices.
Enter Values
Result
Enter values above and click Calculate to see your result.
AI Assistant
Ask about this calculator
I can help you understand the petrol vs diesel cost calculator formula, interpret your results, and answer follow-up questions.
Try asking
Formula
How it works: Calculates monthly fuel spend for each vehicle type, then compares the two to show which is cheaper and by how much. Diesel typically offers 15-25% better fuel economy but costs $0.10 to $0.30 more per gallon or litre.
Worked Example
Comparing Petrol and Diesel Running Costs
Choosing between petrol and diesel affects your fuel budget for years. Diesel engines are more fuel-efficient, but the higher fuel price and maintenance costs can offset savings for low-mileage drivers.
- Diesel engines typically deliver 15-25% better fuel economy than equivalent petrol engines
- Diesel fuel costs $0.10 to $0.30 more per litre or gallon than petrol in most markets
- At 1,500 km/month, diesel can save around $23/month or $278/year on fuel
- High-mileage drivers (20,000+ km/year) benefit most from diesel efficiency
- Diesel maintenance costs run $200 to $500 more per year for injectors and filters
Use this calculator to compare your specific driving pattern and local fuel prices. The right choice depends on your annual mileage, fuel costs in your area, and how long you plan to keep the vehicle.
You can also calculate changes using our Fuel Cost Increase Calculator or Fleet Fuel Expense Calculator.
Frequently Asked Questions
Is diesel always cheaper to run?
Not always. Diesel vehicles get 15-25% better mileage, but diesel fuel often costs $0.10 to $0.30 more per litre. At 1,500 km/month, diesel can save around $23/month, but at lower distances the savings shrink or disappear.
Does this include maintenance costs?
This calculator compares fuel costs only. Diesel vehicles typically cost $200 to $500 more per year in servicing due to injector and particulate filter maintenance, but their engines often last 50,000+ km longer.
What about hybrid or electric vehicles?
This tool compares only petrol vs diesel. Hybrid vehicles typically use 30-50% less fuel than petrol, while fully electric vehicles eliminate fuel costs entirely but have charging costs of roughly $0.03 to $0.10 per km.
At what mileage does diesel become worth it?
Most drivers see diesel savings above 15,000 to 20,000 km per year. At 20,000 km/year with typical prices, diesel can save $250 to $400 annually on fuel alone, which helps offset the higher purchase price.
How do I convert between km/L and MPG?
Multiply km/L by 2.352 to get miles per gallon (US). For example, 14 km/L equals about 33 MPG, and 18 km/L equals about 42 MPG.
Can I embed this Petrol vs Diesel Cost Calculator on my website?
Yes. Click the "Embed" button at the top of this page to customize the size, colors, and theme, then copy the iframe code. Paste it into any HTML page, WordPress site, or CMS. It is completely free, requires no signup, and works on all devices. You can also visit our embed guide at calculory.com/services/embed-calculators for more details.
AI Assistant
Ask about this calculator
I can help you understand the petrol vs diesel cost calculator formula, interpret your results, and answer follow-up questions.
Try asking
Related Calculators
Related Articles
All articles
Agentic ROI Blueprint: Replacing Roles in 2026
In 2026, teams are measuring total capability, not just headcount. Learn how to model the cost of replacing or augmenting full-time roles with an AI agent stack.
Read article
Circular TCO vs Circular Savings: Payback Blueprint 2026
Compare linear ownership costs against circular savings with a practical 2026 model. Calculate annualized cost, lifetime savings, and payback months for sustainable investments.
Read article
GST for AI Freelancers: Foreign Inward Remittance Guide 2026
AI freelancers serving global clients in 2026 can treat eligible work as zero-rated export of services under GST. Learn LUT, IGST refund, RCM on AI tools, and compliance timelines.
Read article
COLA in 2026: How to Negotiate a Cost of Living Raise
A 3% raise with 4% inflation is a pay cut. Learn how to calculate your personal inflation rate and negotiate a COLA raise with data-driven leverage in 2026.
Read articleModern Tools for Every Need
Secure and Private
All calculations run locally. Your data never leaves your browser.
Verified Precision
Precise Calculations Powered by Calculory AI