Battery CCA Requirement Calculator

About this calculator

Cold cranking amps (CCA) rate how much current a battery can deliver for 30 seconds at 0°F (-18°C) while keeping enough voltage to start the engine, and the CCA a car actually needs scales with engine size and fuel type — diesel engines need roughly double the CCA of a similarly-sized petrol engine because of their higher compression ratios, and colder climates require a higher CCA rating because engine oil thickens and battery chemical activity slows in the cold, both making the engine harder to turn over.

Drivers and mechanics check this before buying a replacement battery because installing one with too little CCA for the engine and climate leads to no-start problems specifically in cold weather, even though the same battery might start the car fine on a mild day — CCA needs, unlike most battery specs, are climate-dependent rather than fixed.

This calculator takes your engine displacement, fuel type and winter climate and returns the CCA rating your battery should have, so you can buy a battery that will reliably start your car on the coldest morning of the year, not just an average one.