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Both calculators run independently — change the inputs on either side to compare results.

Tire Size & Speedometer Calculator

Find out exactly how swapping to a different tire size shifts your speedometer reading and changes overall tire diameter. Ideal for wheel upgrade planning, off-road builds, and ensuring legal speedometer accuracy.

Tire Width (mm)

Aspect Ratio (%)

Wheel Diameter (inches)

New Tire Width (Optional) (mm)

New Aspect Ratio (Optional) (%)

Fill in the required fields to see your result.

Automotive

Fuel Cost Per Kilometre Calculator

Works out how much fuel costs you for every kilometre driven, from the fuel price and your vehicle’s consumption in litres per 100 km. It turns abstract fuel-economy figures into a real per-kilometre cost.

Fuel Price ($/L)

Fuel Consumption (L/100km)

Fill in the required fields to see your result.

Key differences

	Tire Size & Speedometer Calculator	Fuel Cost Per Kilometre Calculator
Category	Automotive	Automotive
Inputs required	5	2
Result	Speedometer / Diameter Difference (%)	Fuel Cost Per Kilometre ($/km)
What it does	Find out exactly how swapping to a different tire size shifts your speedometer reading and changes overall tire diameter. Ideal for wheel upgrade planning, off-road builds, and ensuring legal speedometer accuracy.	Works out how much fuel costs you for every kilometre driven, from the fuel price and your vehicle’s consumption in litres per 100 km. It turns abstract fuel-economy figures into a real per-kilometre cost.