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Car Calculator: 16 Free Online Tools in One Place
This free car calculator covers the money and the mechanics of driving. Work out fuel economy and trip cost, compare an EV with a petrol car, plan a car loan, check tyre sizes and estimate stopping distance in one place. Every car calculator result is worked out in your browser, with no sign-up and no upload.
Quick answer: To use the car calculator, pick one of the 16 tools in the menu above, enter your values with the right units and press Calculate. The result appears with notes, and you can copy or print it.
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What the car calculator includes
The car calculator contains 16 separate tools. Choose one from the menu at the top of the page; each tool keeps its own inputs and explains the formula it uses.
| Calculator | What it does |
|---|---|
| Fuel Economy Converter | Convert between L/100 km, km/L, US mpg, UK mpg and miles per litre. |
| Trip Cost Planner | Fuel, tolls, parking, CO₂ and cost per passenger for a one-way or round trip. |
| Vehicle Running Cost Comparison | Compare annual fuel cost of two vehicles and the payback of the efficient one. |
| Stopping Distance | Reaction plus braking distance by speed, road surface and slope. |
| Tyre Size & Speedometer | Tyre diameter, circumference and revolutions; compare a new size and speedometer error. |
| EV Charging Time & Cost | Charging time with tapering, energy from the grid, cost and range added. |
| EV vs Petrol Cost Comparison | Yearly energy, maintenance and CO₂ for an electric vs a fuel car. |
| Vehicle Depreciation | Year-by-year value using declining-balance or straight-line depreciation. |
| Car Loan / Auto Finance | Monthly instalment with down payment, trade-in, tax and fees plus amortization. |
| Total Cost of Ownership | All-in cost per year and per km: depreciation, fuel, insurance, service and more. |
| Payload & Towing Load | Payload used by passengers, cargo and trailer tongue weight vs the limit. |
| Gear Ratio & Road Speed | Speed in every gear at a given RPM and RPM at cruising speed. |
| Engine Displacement & Compression | Displacement from bore, stroke and cylinders; compression ratio and bore/stroke. |
| Horsepower, Torque & Power-to-Weight | Convert torque and RPM to power (and back) with hp, kW, PS and power-to-weight. |
| Acceleration & Quarter-Mile | Average acceleration, g-force, distance covered and estimated quarter-mile time. |
| Travel Time & ETA | Driving time, breaks and arrival time from distance and average speed. |
How to use the car calculator
- Choose a tool. Select the calculation you need from the car calculator menu.
- Check the units. Pick the units you are working in before typing numbers, so the formula uses the right values.
- Enter your values. Fill in every required field. Example values show the expected format.
- Calculate and review. Read the main result, the breakdown and any notes or charts under it.
- Save or compare. Copy, print or download the result, or change one input to compare scenarios.
Who uses this car calculator?
- Drivers comparing fuel costs and planning road trips.
- Car buyers checking loan instalments, depreciation and total cost of ownership.
- EV owners estimating charging time and cost.
- Fleet managers comparing vehicle running costs.
- Car enthusiasts calculating gear speeds, horsepower and engine size.
Tips for accurate results with the car calculator
- Use your real fuel consumption from a few fill-ups for the most accurate trip cost.
- Include insurance, servicing and tyres in total cost of ownership, not only fuel.
- For EV charging, remember that charging slows down above about 80%.
- When changing tyre size, keep the overall diameter within about 3% of the original.
- Stopping distance rises with the square of speed, so small speed increases matter.
Privacy and accuracy
The car calculator runs entirely in your browser. Numbers you type are not sent to Orixiva or stored on a server.
Results use standard published formulas and are rounded for display. They are estimates for planning, study and everyday decisions; for legal, medical, engineering or financial decisions, confirm them with a qualified professional. For background reading, see the fueleconomy.gov.
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Share your feedback
Which car calculator tool did you use, and was the result what you expected? Tell other readers in the comments, or suggest a calculator we should add next. Comments are reviewed before they appear.
Frequently asked questions
Is this car calculator free?
Yes. All 16 car tools are free and work without sign-up.
How do I calculate fuel cost for a trip?
Open Trip Cost Planner, enter distance, fuel economy and fuel price, and add tolls or parking. The calculator shows total cost and cost per passenger.
Can I compare an electric car with a petrol car?
Yes. EV vs Petrol Cost Comparison shows yearly energy cost, maintenance and CO₂ for both.
How is the car loan instalment calculated?
The car loan tool uses the standard amortization formula with your price, down payment, trade-in, interest rate and term, and shows an amortization schedule.
Does a new tyre size change my speedometer?
Yes. Tyre Size & Speedometer compares the old and new diameter and shows the speedometer error.
Which currency does it use?
Amounts default to Rs, and you can enter values in any currency because the formulas are the same.
How do I convert L/100 km to mpg?
US mpg = 235.21 / (L/100 km), and UK mpg = 282.48 / (L/100 km). The Fuel Economy Converter converts between L/100 km, km/L, US mpg, UK mpg and miles per litre in one step.
What does the Trip Cost Planner include?
Fuel for the distance, tolls, parking and CO2 emissions, for a one-way or round trip, with the cost per passenger when the trip is shared.
How long does it take to stop a car?
Stopping distance = reaction distance + braking distance. At 100 km/h with a 1.5-second reaction time the car travels about 42 m before braking even starts. The Stopping Distance tool adjusts for road surface and slope.
Will a different tyre size change my speedometer?
Yes. A larger tyre travels further per turn, so the speedometer reads lower than your real speed. Tyre Size & Speedometer compares two sizes and shows the speed error.
How long does an EV take to charge?
Roughly energy needed / charger power, but charging slows near full. EV Charging Time & Cost models that tapering, adds charging losses and shows the cost and range added.
Is an electric car cheaper to run than a petrol car?
Usually per kilometre, especially with home charging. EV vs Petrol Cost Comparison compares yearly energy, maintenance and CO2 for your own prices and mileage.
How much will my car be worth in a few years?
Vehicle Depreciation estimates the value year by year using declining-balance (a fixed percentage each year) or straight-line depreciation.
How is a car loan payment calculated?
The Car Loan tool uses the standard amortization formula on the price minus down payment and trade-in, plus tax and fees, and shows the monthly payment, total interest and a payment schedule.
What is total cost of ownership?
All costs of having a car: depreciation, fuel or charging, insurance, servicing, tyres, tax and parking. Total Cost of Ownership shows them per year and per kilometre or mile.
How do I check payload and towing limits?
Payload & Towing Load adds passengers, cargo and the trailer tongue weight (usually about 10% of the trailer weight) and compares the total with your vehicle payload limit.
What does the gear ratio calculator show?
Gear Ratio & Road Speed shows your speed in every gear at a given RPM, and the engine RPM at a chosen cruising speed, from gear ratios, final drive and tyre size.
How is engine displacement calculated?
Displacement = pi / 4 x bore squared x stroke x number of cylinders. The tool also gives compression ratio and the bore-to-stroke ratio.
How do I convert torque to horsepower?
Horsepower = torque in lb-ft x RPM / 5,252. In metric, kW = torque in Nm x RPM / 9,549. The tool also converts between hp, kW and PS and gives power-to-weight.
How is a quarter-mile time estimated?
Acceleration & Quarter-Mile uses your 0 to speed time to work out average acceleration, g-force and distance, and estimates a quarter-mile time from power-to-weight.
Can it work out my arrival time with breaks?
Yes. Travel Time & ETA uses distance, average speed and planned breaks to give total driving time and arrival time.
Does it work in miles and kilometres?
Yes. The car tools accept metric and imperial units, and you can use any currency for costs.
Do I need to sign up or install an app?
No. All 16 car tools are free and run in your browser on phone or computer.
Are the results exact?
They are estimates based on standard formulas and the numbers you enter. Real fuel use, stopping distance and depreciation vary, so use them for planning, not legal or safety-critical decisions.
Ready to calculate? Scroll up to the car calculator, choose a tool and get your answer in seconds.